JP3948956B2 - Infrared camera - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention is an improvement of an infrared camera, particularly an infrared camera that stabilizes the output level of an image sensor without requiring an initial setting adjustment when an infrared radiation amount is detected based on a temperature change and an object image is formed. About.
[0002]
[Prior art]
FIG. 7 is a block diagram showing a schematic configuration of a conventional infrared camera 1. The infrared camera 1 has a configuration for detecting infrared rays, an infrared optical system 2 that forms infrared light from a subject, a shutter 3 that blocks infrared light from the infrared optical system 2, and a rear surface of the shutter 3. A window 4 that is disposed on the side and transmits infrared light and an element package 5 in which various elements used in the infrared camera 1 are integrated are included. In this element package 5, an image sensor 6 is disposed on the imaging surface of the infrared optical system 2. The image sensor 6 includes an element temperature monitor 7 that monitors the temperature of the image sensor 6, and the temperature of the image sensor 6. The thermoelectric elements 8 that change the temperature are respectively thermally connected. A DC power source 9 is also connected to the image sensor 6.
[0003]
Further, the circuit configuration of the infrared camera 1 includes a driver circuit 10 connected to the image sensor 6, a temperature control circuit 11 that is connected to the element temperature monitor 7 and the thermoelectric element 8 and controls the temperature of the image sensor 6 to be constant, and an image sensor 6, an amplification circuit 12 that amplifies the output of 6, a correction processing circuit 13 that corrects the sensitivity, offset, and defect of the amplified element output, and a display that converts the corrected element output into a desired display format to image a subject. In the processing circuit 14, the shutter 3, the driver circuit 10, the correction processing circuit 13, the timing generation circuit 15 for supplying operation timing to the display processing circuit 14, and the element output level setting switching for switching the element output level in the imaging device 6. The switch 16, the first element output level setting circuit 17 for setting the element output level, and an element different from the first element output level setting circuit 17 A second element output level setting circuit 18 for setting the force level, an element control temperature switching switch 19 for switching the element control temperature, a first element control temperature setting circuit 20 for setting the element control temperature, and a first element control. A second element control temperature setting circuit 21 that sets an element control temperature different from the temperature setting circuit 20, a temperature sensor 22 that monitors the temperature inside the camera, and an element output level switching when the output of the temperature sensor 22 exceeds a certain threshold value It includes a comparator 23 that switches between the switch 16 and the element control temperature changeover switch 19, a temperature switching threshold setting circuit 24 that sets a temperature switching threshold of the comparator 23, and the like. Each configuration described above is housed in the housing 25.
[0004]
FIG. 8 shows a configuration of the image sensor 6 and actually has a configuration in which a plurality of pixels are arranged in a matrix, but a single pixel is shown for the sake of simplicity of explanation. The image sensor 6 includes a horizontal scanning circuit 26 that selects pixels in the horizontal direction, a vertical scanning circuit 27 that selects pixels in the vertical direction, a first transistor 28 that turns on / off current to the pixels in the horizontal direction, and an infrared detection pixel. 29, a second transistor 30 for turning ON / OFF the current to the pixel in the vertical direction, and a third transistor 31 for controlling the current flowing through the infrared detection pixel 29 and changing the element output level.
[0005]
FIG. 9 shows a schematic structure of the infrared detection pixel 29. This structure is, for example, a microbolometer described in Japanese Patent Application Laid-Open No. 7-509057, and the infrared detection element 32 is a thermal infrared detection element such as a bolometer or a diode. In the infrared detection pixel 29, the infrared detection element 32 is supported by a bridge structure 33. Therefore, the bridge structure 33 has a gap 34 formed therein. The bridge structure 33 is formed on the silicon substrate 35.
[0006]
FIG. 10 shows a schematic configuration of the temperature control circuit 11. The element temperature monitor circuit 36 generates a value proportional to the output of the element temperature monitor 7. The output of the element temperature monitor circuit 36 and the element control temperature changeover switch 19 It includes a subtractor 37 for obtaining the error of the selected output, an integration circuit 38 for integrating the obtained error, a power supply circuit 39 for converting the error into power and supplying it to the thermoelectric element 8 and the like.
[0007]
The operation of the conventional infrared camera 1 configured as described above will be described. A temperature that is a threshold value (for example, 25 ° C.) is set in advance in the temperature switching threshold setting circuit 24, and a control temperature (for example, 5 ° C.) and a second element control temperature are set in the first element control temperature setting circuit 20. A control temperature (for example, 50 ° C.) at the time of high temperature control is set in each circuit 21. First, immediately after the power is turned on, the temperature inside the housing 25 is read by the temperature sensor 22, and the read temperature and the temperature switching threshold set by the temperature switching threshold setting circuit 24 are compared by the comparator 23. Based on whether the output is low, the element control temperature switch 19 connects either the output of the first element control temperature setting circuit 20 or the output of the second element control temperature setting circuit 21 to the temperature control circuit 11. The element temperature monitor circuit 36 included in the temperature control circuit 11 generates a value proportional to the output of the element temperature monitor 7. An error between the output of the element temperature monitor circuit 36 and the output of the element control temperature changeover switch 19 is obtained by the subtractor 37, and the error is integrated by the integration circuit 38. This error is supplied as power to the thermoelectric element 8 via the power supply circuit 39, and the temperature of the image sensor 6 is controlled so as to cancel the error. As a result, the control temperature of the image sensor 6 can be controlled to be constant.
[0008]
The image sensor 6 is driven by a DC power supply 9 and a driver circuit 10 as shown in FIG. The horizontal scanning circuit 26 and the vertical scanning circuit 27 are operated based on a signal at a desired timing supplied from the driver circuit 10, and a predetermined infrared detection pixel 29 is selected. As a result, a current flows from the DC power source 9 through the second transistor 30, the selected infrared detection pixel 29, the first transistor 28, and the third transistor 31.
[0009]
At this time, since the infrared detection pixel 29 has a gap 34 by the bridge structure 33 as shown in FIG. 9, when infrared light imaged by the infrared optical system 2 enters the infrared detection pixel 29, the infrared detection element 32. The temperature changes with respect to the silicon substrate 35. Due to this temperature change, characteristics such as the resistance value of the infrared detecting element 32 change, and the flowing current changes. By taking out this change in current as a change in the output voltage of the third transistor 31, the incident infrared light is output as a voltage and supplied to the amplifier circuit 12.
[0010]
Here, when the control temperature of the image sensor 6 is changed by the selection of the element control temperature setting circuits 20 and 21, the output of the image sensor 6 changes in the same manner as when infrared light is incident. That is, as apparent from the characteristic change of the infrared detection pixel 29 shown in FIG. 11, the output voltage level drifts greatly with temperature, deviates from the input range of the amplifier circuit 12, and appropriate processing cannot be performed. Therefore, the voltage supplied to the third transistor 31 is the set temperature by the first element control temperature setting circuit 20 and the output of the first element output level setting circuit 17 and the output of the second element output level setting circuit 18, respectively. And the second element control temperature setting circuit 21 adjusts at the time of initial setting so that the output levels become equal to the set temperature. Then, the element output level is kept constant even when the element control temperature is switched by switching according to the element control temperature by the element output level changeover switch 16.
[0011]
Further, when the temperature inside the housing 25 changes so as to cross the threshold set by the temperature switching threshold setting circuit 24 due to a change in the ambient environment temperature or the like, the element control temperature switch 19 and the element output level switch 16 are switched by the comparator 23. The connection of is switched. The output of the image sensor 6 is amplified by the amplifying circuit 12 so that sufficient S / N can be secured for correcting the sensitivity and offset variation and the pixel defect by the correction processing circuit 13. After the correction processing circuit 13 corrects variations in sensitivity and offset and pixel defects, the display processing circuit 14 converts it into, for example, a television display format and outputs it.
[0012]
[Problems to be solved by the invention]
However, in the conventional infrared camera, as described above, it is necessary to adjust the element output level setting circuit at the time of assembly so that the element output levels before and after the switching of the control temperature of the image pickup element are equal, and the initial adjustment is performed. In addition to being complicated, the circuit configuration is also complicated. Also, since the element output level setting is an intermittent operation based on the switching of the element output level selector switch, the element output level deviates from the amplifier input range until the element temperature stabilizes, such as when the control temperature is switched, and a normal image is displayed. There was an unobtainable time.
[0013]
The present invention has been made in view of the above-described conventional problems, and an object of the present invention is to obtain an infrared camera that does not require adjustment of the element output level of the image sensor and can always obtain a stable normal image.
[0014]
[Means for Solving the Problems]
In order to achieve the above object, the present invention is an infrared camera that detects the amount of infrared radiation based on a change in temperature and images a subject image, and includes an infrared detection pixel having sensitivity to incident infrared radiation, and the infrared radiation A dummy pixel that is arranged in the vicinity of the detection pixel and has an equivalent electrical characteristic and that continuously outputs a signal corresponding to its own temperature without waiting for sensitivity to the incident infrared ray, An image sensor that outputs a signal according to intensity, Record Based on the output from the me pixel, Infrared detection pixel And an element output level control circuit that controls the output level to be constant.
[0015]
In order to achieve the above object, according to the present invention, in the above configuration, the dummy pixel supports the infrared detection pixel with a solid support, and leaks a temperature change due to infrared light through the support. Therefore, the sensitivity to infrared rays is suppressed.
[0016]
In order to achieve the above object, according to the present invention, in the above configuration, the imaging element has a plurality of dummy pixels, and continuously calculates an average value of signals according to the temperatures of the plurality of dummy pixels themselves. Output and control the output level.
[0017]
In order to achieve the above object, according to the present invention, in the above configuration, the element output level control circuit integrates an error between an output signal of the dummy pixel and a preset element output level command value, and the imaging It is assumed that the element output level is made constant by feeding back to the control means for controlling the element output level in the element.
[0018]
In order to achieve the above object, according to the present invention, in the configuration described above, the present invention provides a thermal control element that supplies or cools heat to the image sensor according to supplied power, and a temperature monitor that monitors the temperature of the image sensor. An element control temperature setting circuit for setting a plurality of element control temperatures; a temperature sensor for monitoring the temperature inside the camera; and an element control temperature switching switch for switching the output of the element control temperature setting circuit in accordance with the output of the temperature sensor; And a temperature control circuit for supplying power to the thermal control element to control the temperature of the imaging element to a temperature selected by the element control temperature changeover switch.
[0019]
DETAILED DESCRIPTION OF THE INVENTION
DESCRIPTION OF EXEMPLARY EMBODIMENTS Hereinafter, preferred embodiments of the invention will be described with reference to the drawings.
[0020]
Embodiment 1 FIG.
FIG. 1 is a schematic block diagram of an infrared camera 40 according to Embodiment 1 of the present invention. In addition, the same code | symbol is attached | subjected and demonstrated to the same structural member as the conventional infrared camera 1 shown in FIG.
[0021]
The infrared camera 40 has a configuration for detecting infrared rays, an infrared optical system 2 that forms infrared light from a subject, a shutter 3 that blocks infrared light from the infrared optical system 2, and the rear surface of the shutter 3. A window 4 that is disposed on the side and transmits infrared light and an element package 5 in which various elements used in the infrared camera 40 are integrated are included. In this element package 5, an image pickup device 41 is disposed on the imaging surface of the infrared optical system 2, and a DC power supply 9 is connected to the image pickup device 41.
[0022]
The circuit configuration of the infrared camera 40 includes a driver circuit 10 connected to the image sensor 41, an amplifier circuit 12 that amplifies the output of the image sensor 41, and a correction process that corrects the sensitivity, offset, and defects of the amplified element output. The circuit 13 supplies the operation timing to the display processing circuit 14 that converts the corrected element output into a desired display format to image the subject, the shutter 3, the driver circuit 10, the correction processing circuit 13, and the display processing circuit 14. A timing generation circuit 15 is included. Each configuration described above is housed in the housing 25.
[0023]
In the infrared camera 40 shown in the first embodiment, an element output level control circuit 42 for making the element output level constant is connected to the imaging element 41.
[0024]
FIG. 2 shows a schematic configuration of the element output level control circuit 42. The element output level control circuit 42 is connected to a DC power source 9 and is connected to an element output level command value setting circuit 43 for setting the element output level of the image sensor 41 and a dummy pixel 44 described later. It includes a subtractor 45 for obtaining an error between the element output level command value from the setting circuit 43 and the input value from the dummy pixel 44, and an integrating circuit 46 for integrating the calculated error.
[0025]
FIG. 3 shows a schematic configuration of the image sensor 41. The actual image sensor 41 has a configuration in which a plurality of pixels are arranged in a matrix, but in order to simplify the description, a single pixel is shown in FIG.
[0026]
The image sensor 41 includes a horizontal scanning circuit 26 that selects pixels in the horizontal direction, a vertical scanning circuit 27 that selects pixels in the vertical direction, a first transistor 28 that turns on / off current to the pixels in the horizontal direction, and an infrared detection pixel 29. The second transistor 30 for turning on / off the current to the pixels in the vertical direction, and the third transistor 31 for controlling the current flowing through the infrared detection pixel 29 and changing the element output level. Accordingly, in the actual imaging device 41, there are the first transistor 28 and the second transistor 30 corresponding to the number of rows and columns of the plurality of infrared detection pixels 29 arranged in a matrix, and the horizontal scanning circuit 26 and By selecting predetermined first transistors 28 and second transistors 30 in rows and columns by the vertical scanning circuit 27, the infrared detection pixels 29 are alternatively selected.
[0027]
In the imaging device 41 of the first embodiment, the dummy pixel 44 that outputs a signal corresponding to its own temperature regardless of the intensity of incident infrared light, and the current flowing through the dummy pixel 44 are controlled to output the device. A fourth transistor 47 for changing the level is included.
[0028]
Here, the infrared detection pixel 29 has the same configuration as the conventional element shown in FIG. That is, the infrared detection element 32 is a thermal infrared detection element such as a bolometer or a diode, and the infrared detection element 32 is supported by the bridge structure 33. Therefore, the bridge structure 33 has a gap 34 formed therein. The bridge structure 33 is formed on the silicon substrate 35. Therefore, when infrared rays are incident on the infrared detection pixels 29, the infrared detection elements 32 change the temperature of the infrared detection elements 32 with respect to the silicon substrate 35 in accordance with the amount of incidence. On the other hand, in the dummy pixel 44, as shown in FIG. 4, the infrared detection element 32, which is a thermal type infrared detection element such as a bolometer or a diode, is supported by a solid bridge structure 48 having no gap. . The bridge structure 48 is formed on the silicon substrate 35. Therefore, in the dummy pixel 44, even if infrared rays are incident on the infrared detection element 32, the heat caused by the incident infrared rays immediately leaks to the silicon substrate 35 via the bridge structure 48. It does not show a change, that is, a part having no sensitivity to infrared rays.
[0029]
As described above, the infrared detection pixel 29 and the dummy pixel 44 can be easily created only by selecting either the bridge structure 33 or the bridge structure 48.
[0030]
In the imaging element 41 configured as described above, the infrared detection pixel 29 formed by the infrared detection element 32 supported by the bridge structure 33 having a gap has a predetermined timing at which a predetermined element is supplied from the driver circuit 10. It is selected by a horizontal scanning circuit 26 and a vertical scanning circuit 27 that operate based on the signal. By performing this selection, the current from the DC power supply 9 flows to the second transistor 30, the selected infrared detection pixel 29, the first transistor 28, and the third transistor 31. At this time, the selected infrared detection pixel 29 outputs a value corresponding to the amount of incident infrared rays. On the other hand, the dummy pixel 44 formed by the infrared detection element 32 supported by the bridge structure 48 having no air gap is completely independent of the horizontal scanning circuit 26 and the vertical scanning circuit 27 and receives a current from the DC power supply 9. Receive. At this time, the dummy pixel 44 always outputs a value based on its own temperature change, that is, a temperature change that is not affected by the infrared ray, without any temperature change caused by the infrared ray.
[0031]
Next, the operation will be described. Since the infrared camera 40 does not include the conventional element temperature monitor 7, thermoelectric element 8, and temperature control circuit 11, the temperature of the image sensor 41 changes according to the operating environment temperature. That is, the element output levels of the infrared detection pixel 29 and the dummy pixel 44 change according to the temperature change. Here, it is assumed that the dummy pixel 44 and the infrared detection pixel 29 have substantially the same characteristics with respect to the operating temperature. At this time, since the dummy pixel 44 has a solid bridge structure 48 as shown in FIG. 4 and does not have a gap as the infrared detection pixel 29 has, the temperature of the infrared detection element 32 becomes equal to the silicon substrate 35. A signal according to the temperature of the dummy pixel 44 itself is output regardless of the intensity of incident infrared rays. The subtracter 45 subtracts the element output level command value set in the element output level command value setting circuit 43 from the element output level of the dummy pixel 44 to obtain an error. This error is integrated by the integration circuit 46 and fed back to the third transistor 31 and the fourth transistor 47 so as to cancel the error. Here, the third transistor 31 and the fourth transistor 47 have substantially the same characteristics with respect to the feedback from the integration circuit 46, so that the element output level of the infrared detection pixel 29 is the element output level command value or In the vicinity, it is always kept constant.
[0032]
As described above, according to the first embodiment, the element output level is kept constant by continuous control regardless of the operating temperature of the image sensor 41, so that the element temperature control and the element output level adjustment (initial adjustment) become unnecessary. Work during assembly becomes easy. In addition, an infrared camera can be obtained in which the circuit scale and power consumption are reduced and images are not interrupted over a wide temperature range.
[0033]
In the image pickup device 41, the number and positions of the dummy pixels 44 are arbitrary, and even one can sufficiently function. For example, as shown in FIG. 5, infrared detection pixels arranged in a matrix form 29, for example, dummy pixels 44 are arranged at four corners, and an average value of signals corresponding to the temperature of a plurality of (for example, four) dummy pixels 44 is continuously output and calculated by the integration circuit 46. If the output level is controlled based on the average value, the operating state of the image sensor 41 can be recognized more accurately and the element output level can be automatically adjusted, so that a better image can be obtained. Can do.
[0034]
Embodiment 2. FIG.
Depending on the characteristics of the material used for the infrared detection element 32 in the image pickup element 41, there may be a large difference in offset and sensitivity variation between pixels depending on the operating temperature. FIG. As with the conventional infrared camera 1 shown, element temperature control may be required. The second embodiment shown in FIG. 6 is a block diagram showing a schematic configuration of an infrared camera 49 to which the technique used in the first embodiment is applied in such a case.
[0035]
In the infrared camera 49, the same members as those in the first embodiment and the prior art will be described with the same reference numerals. An infrared optical system 2 that forms infrared light from a subject, a shutter 3 that blocks infrared light from the infrared optical system 2, and a window 4 that is disposed on the back side of the shutter 3 and transmits infrared light. And an element package 5 in which various elements used for the infrared camera 49 are integrated. In this element package 5, the same image sensor 41 as in the first embodiment is arranged on the imaging surface of the infrared optical system 2, but in the second embodiment, the image sensor 41 is connected to the image sensor 41. An element temperature monitor 7 that monitors the temperature of the image sensor 41 and a thermoelectric element 8 that changes the temperature of the image sensor 41 are thermally connected to each other. A DC power supply 9 is also connected to the image sensor 41.
[0036]
Further, the circuit configuration of the infrared camera 49 includes a driver circuit 10 connected to the image sensor 41, a temperature control circuit 11 connected to the element temperature monitor 7 and the thermoelectric element 8 to control the temperature of the image sensor 41 to be constant, and an image sensor An amplifying circuit 12 for amplifying the output of 41, a correction processing circuit 13 for correcting the sensitivity, offset and defect of the amplified element output, a display processing circuit 14 for converting the corrected element output into a desired display format, and the shutter 3 A timing generation circuit 15 for supplying operation timing to the driver circuit 10, the correction processing circuit 13 and the display processing circuit 14, an element control temperature changeover switch 19 for switching the element control temperature, and a first element control for setting the element control temperature. Temperature setting circuit 20, second element control temperature setting circuit 2 for setting element control temperature different from first element control temperature setting circuit 20 A temperature sensor 22 for monitoring the temperature inside the camera, a comparator 23 for switching the element control temperature switch 19 when the output of the temperature sensor 22 exceeds a certain threshold, and a temperature switching threshold for setting the temperature switching threshold of the comparator 23 A setting circuit 24 and the like are included. Each configuration described above is housed in the housing 25.
[0037]
Also in the infrared camera 49 shown in the second embodiment, an element output level control circuit 42 for making the element output level of the imaging element 41 constant is connected. The configuration of the element output level control circuit 42 is the same as that of the first embodiment. The configuration of the image sensor 41 is also the same as that of the first embodiment.
[0038]
Next, the operation will be described. When the element control temperature is switched as in the conventional case, the infrared detection pixel 29 and the dummy pixel 44 exhibit a temperature change at the same rate under the control of the temperature control circuit 11. At this time, by using the image sensor 41 having the dummy pixel 44 and the fourth transistor 47 similar to the first embodiment and the element output level control circuit 42, the output of the image sensor 41 is not affected by the element control temperature. It becomes possible to keep the level constant, and even when it is necessary to perform element temperature control, adjustment of the element output level setting for each operating temperature can be made unnecessary.
[0039]
According to the second embodiment, it is possible to easily perform an assembly that does not require adjustment of the element output level setting when the characteristic variation between pixels is large due to the operating temperature of the infrared detection element 32 and the conventional element temperature control is required. Can be obtained.
[0040]
【The invention's effect】
As described above, according to the present invention, an infrared detection pixel having sensitivity to incident infrared rays, and a pixel which is disposed in the vicinity of the infrared detection pixel and has equivalent electrical characteristics, has sensitivity to incident infrared rays. A dummy pixel that continuously outputs a signal corresponding to its own temperature without waiting, an image sensor that outputs a signal according to the intensity of incident infrared light, and an output from the infrared detection pixel and the dummy pixel And an element output level control circuit for controlling the output level of the image sensor to be constant, and by configuring the infrared camera, the element output level is kept constant regardless of the operating temperature of the image sensor. Temperature control and element output level adjustment are not required, the assembly work can be facilitated, the circuit scale and power consumption are reduced, and a wide temperature range is achieved. Image can be obtained an infrared camera is not interrupted in the range.
[0041]
Further, according to the present invention, in the above configuration, the dummy pixel leaks the temperature change due to the infrared ray through the support by supporting the infrared detection pixel with the solid support, and suppresses the sensitivity to the infrared. The dummy pixel can be configured with an easy configuration, and the infrared detection pixel and the dummy pixel can be easily made separately.
[0042]
Further, according to the present invention, in the above configuration, by having a plurality of dummy pixels, and continuously outputting an average value of signals corresponding to the temperatures of the plurality of dummy pixels themselves to control the output level, The output level of the image sensor can be made more accurate.
[0043]
According to the invention, in the above configuration, the element output level control circuit integrates an error between the output signal of the dummy pixel and a preset element output level command value, and controls the element output level in the image sensor. Since the element output level is made constant by feeding back to the control means, it is possible to control the element output level in real time with an easy configuration.
[0044]
According to the invention, in the above-described configuration, the image sensor is set with a thermal control element that supplies or cools heat according to the supplied power, a temperature monitor that monitors the temperature of the image sensor, and a plurality of element control temperatures. An element control temperature setting circuit, a temperature sensor for monitoring the internal temperature of the camera, an element control temperature switching switch for switching the output of the element temperature setting circuit in accordance with the output of the temperature sensor, and a temperature selected by the element temperature switching switch In order to control the temperature of the image sensor, a temperature control circuit that supplies power to the thermal control element is included. Therefore, even when the characteristic variation between pixels due to the operating temperature of the image sensor is large and the element temperature control is required, the dummy is controlled. Red that operates satisfactorily without adjusting the element output level setting for each operating temperature by the operation of the element output level control circuit using the element It is possible to obtain a line camera.
[Brief description of the drawings]
FIG. 1 is a block diagram illustrating a schematic configuration of an infrared camera according to Embodiment 1 of the present invention.
FIG. 2 is a block diagram showing a configuration of an element output level control circuit of the infrared camera according to Embodiment 1 of the present invention.
FIG. 3 is an explanatory diagram illustrating a structure of a dummy pixel of the infrared camera according to Embodiment 1 of the present invention.
FIG. 4 is a structural diagram showing a structure of a dummy pixel in Embodiment 1 of the infrared camera according to the present invention.
FIG. 5 is a structural diagram showing a structure when a plurality of dummy pixels are arranged in the infrared camera according to the first embodiment of the present invention.
FIG. 6 is a block diagram illustrating a schematic configuration of an infrared camera according to Embodiment 2 of the present invention.
FIG. 7 is a block diagram showing a schematic configuration of a conventional infrared camera.
FIG. 8 is a block diagram showing a configuration of an image sensor in a conventional infrared camera.
FIG. 9 is a structural diagram showing the structure of an infrared detection pixel in a conventional infrared camera.
FIG. 10 is a block diagram showing a configuration of a temperature control circuit in a conventional infrared camera.
FIG. 11 is a diagram for explaining the behavior of the image sensor with respect to the control temperature.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Infrared camera, 2 Infrared optical system, 3 Shutter, 4 Window, 5 element package, 10 Driver circuit, 12 Amplifier circuit, 13 Correction processing circuit, 14 Display processing circuit, 15 Timing generation circuit, 40 Infrared camera, 41 Image sensor 42 Element output level control circuit.

Claims (5)

An infrared camera that detects the amount of infrared radiation based on temperature changes and images a subject image,
An infrared detection pixel that is sensitive to incident infrared rays, and a pixel that is arranged in the vicinity of the infrared detection pixels and that has equivalent electrical characteristics, and continuously outputs a signal corresponding to its own temperature without waiting for sensitivity to incident infrared rays. An image sensor that outputs a signal corresponding to the intensity of incident infrared rays,
Based on the output from the previous Kida Me pixel, and the element output level control circuit for an output level of the infrared detection pixel is controlled to be constant,
Infrared camera characterized by including. The dummy pixel is
The infrared camera according to claim 1, wherein the infrared detection pixel is supported by a solid support, and sensitivity to infrared is suppressed by leaking a temperature change due to infrared through the support.   2. The image pickup device according to claim 1, wherein the image pickup device has a plurality of dummy pixels, and continuously outputs an average value of signals corresponding to the temperatures of the plurality of dummy pixels themselves to control an output level. Item 3. An infrared camera according to item 2. The element output level control circuit includes:
The element output level is made constant by integrating an error between the output signal of the dummy pixel and a preset element output level command value and feeding back to the control means for controlling the element output level in the image sensor. The infrared camera according to any one of claims 1 to 3. A heat control element for supplying heat or cooling to the image sensor in accordance with power supplied;
A temperature monitor for monitoring the temperature of the image sensor;
An element control temperature setting circuit for setting a plurality of element control temperatures;
A temperature sensor that monitors the internal temperature of the camera;
An element control temperature switching switch for switching the output of the element control temperature setting circuit according to the output of the temperature sensor;
A temperature control circuit for supplying power to the thermal control element to control the temperature of the imaging element to a temperature selected by the element control temperature changeover switch;
The infrared camera according to claim 1, comprising:

Images