JP2003198931A - Infrared camera - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To obtain an infrared camera which doesn't require temperature control of an imaging device and device output level adjustment and stably keeps the device output level independently of the operation temperature. <P>SOLUTION: An imaging device 41 is used which has a dummy pixel which has electric characteristics equivalent to those of an infrared detector and is not sensitive to incident infrared rays and continuously outputs a signal caused by the operation temperature of the imaging device 41 without passing a scaning circuit for pixel selection, and the device output level is fed back to the imaging device 41 by a device output level control circuit 42 so as to cancel the temperature fluctuation of the output level, and thus the device output level is kept fixed. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an infrared camera, and in particular, when the infrared radiation amount is detected by a temperature change and a subject image is imaged, initial setting adjustment is not required.
The present invention relates to an improvement of an infrared camera that stabilizes the output level of an image sensor.

[0002]

2. Description of the Related Art FIG. 7 is a block diagram showing a schematic configuration of a conventional infrared camera 1. The infrared camera 1 is configured to detect infrared light, and an infrared optical system 2 that forms an infrared light from a subject, a shutter 3 that blocks the infrared light from the infrared optical system 2, and a back surface of the shutter 3. It includes a window 4 arranged on the side and transmitting infrared light, and an element package 5 in which various elements used in the infrared camera 1 are integrated. In this element package 5, an image pickup element 6 is arranged on the image plane of the infrared optical system 2, and the image pickup element 6 is provided in the image pickup element 6.
Element temperature monitor 7 for monitoring the temperature of the
The thermoelectric elements 8 for changing the temperature are thermally connected. A DC power supply 9 is also connected to the image sensor 6.

As the circuit configuration of the infrared camera 1, a driver circuit 10 connected to the image pickup element 6, a temperature control circuit 11 connected to the element temperature monitor 7 and the thermoelectric element 8 to control the temperature of the image pickup element 6 at a constant level. An amplifier circuit 12 that amplifies the output of the image sensor 6, a correction processing circuit 13 that corrects the sensitivity, offset, and defect of the amplified element output, and converts the corrected element output into a desired display format to image a subject. In the display processing circuit 14 for performing the above, the shutter 3, the driver circuit 10, the correction processing circuit 13, the timing generation circuit 15 for supplying the operation timing to the display processing circuit 14, and the image sensor 6, the element output for switching the setting of the element output level. Level setting changeover switch 16, first element output level setting circuit 17 for setting element output level, first element output level setting circuit 17 The second element output level setting circuit 18 for setting the different elements output level, the element control temperature change-over switch 19 for switching element control temperature, the first element control temperature setting circuit 20 for setting the device control temperature, first
Second element control temperature setting circuit 21 that sets an element control temperature different from the element control temperature setting circuit 20 of FIG. 2, a temperature sensor 22 that monitors the temperature inside the camera, and an element when the output of the temperature sensor 22 exceeds a certain threshold value. It includes a comparator 23 for switching between the output level changeover switch 16 and the element control temperature changeover switch 19, a temperature changeover threshold setting circuit 24 for setting a temperature changeover threshold of the comparator 23, and the like. The above-described components are housed in the housing 25.

FIG. 8 shows the structure of the image pickup device 6, which actually has a structure in which a plurality of pixels are arranged in a matrix, but a single pixel is shown for simplification of description. The image sensor 6 includes a horizontal scanning circuit 26 for selecting pixels in the horizontal direction, a vertical scanning circuit 27 for selecting pixels in the vertical direction, and a first ON / OFF switch for turning on / off a current to the pixels in the horizontal direction.
Transistor 28, infrared detection pixel 29, second transistor 3 for turning on / off the current to the vertical pixel
0, a third transistor 31 for controlling the current flowing through the infrared detection pixel 29 and changing the element output level.

Further, FIG. 9 shows a schematic structure of the infrared detection pixel 29. This structure is, for example,
A microbolometer described in No. 509057,
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 the bridge structure 33. Therefore, the bridge structure 33 has a void 34 formed therein. The bridge structure 33 is formed on the silicon substrate 35.

FIG. 10 shows a schematic structure of the temperature control circuit 11, which includes an element temperature monitor circuit 36 for generating a value proportional to the output of the element temperature monitor 7 and an element temperature monitor circuit 3.
A subtracter 37 for obtaining an error between the output of 6 and the output selected by the element control temperature changeover switch 19, an integrating circuit 38 for integrating the obtained error, a power supply circuit 39 for converting the error into electric power and supplying it to the thermoelectric element 8. Contains.

The operation of the conventional infrared camera 1 configured as described above will be described. The temperature (for example, 25 ° C.) serving as the threshold value is set in the temperature switching threshold value setting circuit 24 in advance
The element control temperature setting circuit 20 includes a control temperature (for example, 5 ° C.) during low temperature control and a second element control temperature setting circuit 21.
Then, the control temperature (for example, 50 ° C.) at the time of high temperature control is set respectively. 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 is compared with the temperature switching threshold set by the temperature switching threshold setting circuit 24 by the comparator 23 to determine whether the temperature is higher than the threshold temperature. Based on whether it is low, the element control temperature changeover switch 19
Of the element control temperature setting circuit 20 or the output of the second element control temperature setting circuit 21
Connect to. 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. The subtractor 37 calculates the error between the output of the element temperature monitor circuit 36 and the output of the element control temperature changeover switch 19, and the integrating circuit 38 integrates the error. This error is supplied as power to the thermoelectric element 8 via the power supply circuit 39, and the temperature of the image pickup element 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.

The image pickup device 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 operate based on the signal of the desired timing supplied from the driver circuit 10, and the predetermined infrared detection pixel 29 is selected. As a result, a current flows from the DC power supply 9 through the second transistor 30, the selected infrared detection pixel 29, the first transistor 28, and the third transistor 31.

At this time, since the infrared detection pixel 29 has the void 34 formed by the bridge structure 33 as shown in FIG. 9, when the infrared light imaged by the infrared optical system 2 enters the infrared detection pixel 29, the infrared The temperature of the detection element 32 changes with respect to the silicon substrate 35. Due to this temperature change, characteristics such as the resistance value of the infrared detection element 32 change, and the flowing current changes. This change in current is applied to the third transistor 3
By taking out as the output voltage change of 1, the incident infrared light is output as a voltage and supplied to the amplifier circuit 12.

Here, in the image pickup device 6, when the control temperature changes due to the selection of the element control temperature setting circuits 20 and 21, the output of the image pickup device 6 changes as in the case where infrared light is incident. That is, the infrared detection pixel 2 shown in FIG.
As is clear from the characteristic change of 9, the output voltage level largely drifts with temperature, deviates from the input range of the amplifier circuit 12, and proper processing cannot be performed. Therefore, the voltage supplied to the third transistor 31 is set by the output of the first element output level setting circuit 17 and the output of the second element output level setting circuit 18 respectively by the temperature set by the first element control temperature setting circuit 20. And the second element control temperature setting circuit 2
Adjustment is made at the time of initial setting so that the output levels become equal in correspondence with the set temperature of 1. Then, the element output level changeover switch 16 performs switching in accordance with the element control temperature so that the element output level becomes constant even when the element control temperature is switched.

Further, when the temperature inside the housing 25 changes so as to cross the threshold value set by the temperature switching threshold value setting circuit 24 due to changes in the ambient environment temperature or the like, the comparator 23
Thus, the connection between the element control temperature changeover switch 19 and the element output level changeover switch 16 is switched. The output of the image sensor 6 is amplified by the amplifier circuit 12 so that the correction processing circuit 13 can secure a sufficient S / N for correcting variations in sensitivity and offset and pixel defects. After the correction processing circuit 13 corrects the variations in sensitivity and offset and the pixel defect, the display processing circuit 14 converts the data into a television display format or the like and outputs it.

[0012]

However, in the conventional infrared camera, as described above, the element output level setting circuit of the element output level setting circuit is assembled 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 become equal. There is a problem that adjustment is required, initial adjustment is complicated, and circuit configuration is complicated. Also, since the element output level setting is an intermittent operation based on the switching of the element output level changeover switch, the element output level deviates from the amplifier input range until the element temperature stabilizes, such as when changing the control temperature, and a normal image is displayed. There was a dead time.

The present invention has been made in view of the above conventional problems, and an object of the present invention is to obtain an infrared camera which does not require element output level adjustment of an image pickup element and can always obtain a stable and normal image.

[0014]

In order to achieve the above object, the present invention is an infrared camera for detecting the amount of infrared radiation by temperature change and imaging a subject image. An infrared detection pixel having a pixel having a similar electrical property, which is arranged in the vicinity of the infrared detection pixel and which outputs a signal corresponding to its own temperature continuously without waiting for sensitivity to the incident infrared rays. And an image sensor that outputs a signal according to the intensity of incident infrared light, and an element that controls the output level of the image sensor to be constant based on the outputs from the infrared detection pixel and the dummy pixel. And an output level control circuit.

In order to achieve the above-mentioned object, in the present invention according to the above-mentioned structure, the dummy pixel supports the infrared detection pixel with a solid support, and a temperature change due to infrared rays is passed through the support. By leaking, the sensitivity to infrared rays is suppressed.

In order to achieve the above object, according to the present invention, in the above structure, the image pickup device has a plurality of dummy pixels, and an average value of signals according to temperatures of the plurality of dummy pixels themselves is calculated. It shall be continuously output and the output level shall be controlled.

In order to achieve the above object, in the present invention according to the above structure, 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. The element output level is made constant by feeding back to the control means for controlling the element output level in the image pickup element.

In order to achieve the above-mentioned object, the present invention has the above-mentioned structure, and monitors the temperature of the image pickup device and a thermal control device for supplying or cooling heat according to the supplied power. A temperature monitor, an element control temperature setting circuit that sets a plurality of element control temperatures, a temperature sensor that monitors the camera internal temperature, and an element control temperature that switches the output of the element control temperature setting circuit according to the output of the temperature sensor. A changeover switch and a temperature control circuit for supplying electric power to the thermal control element for controlling the temperature of the image pickup element to the temperature selected by the element control temperature changeover switch.

[0019]

BEST MODE FOR CARRYING OUT THE INVENTION Preferred embodiments of the present invention will be described below with reference to the drawings.

Embodiment 1. 1 is a schematic block diagram of an infrared camera 40 according to a first embodiment of the present invention. In addition, the same components as those of the conventional infrared camera 1 shown in FIG.

The infrared camera 40 is configured to detect infrared rays, and the infrared optical system 2 forms an image of infrared light from a subject.
And a shutter 3 that blocks infrared light from the infrared optical system 2.
And a window 4 arranged on the back side of the shutter 3 for transmitting infrared light, and an element package 5 in which various elements used in the infrared camera 40 are integrated. In this element package 5, the image pickup element 4 is formed on the image plane of the infrared optical system 2.
1 is arranged, and the DC power source 9 is connected to the image pickup element 41.

As the circuit configuration of the infrared camera 40, the driver circuit 10 connected to the image pickup element 41, the amplifier circuit 12 for amplifying the output of the image pickup element 41, the sensitivity of the amplified element output, the offset and the defect are corrected. Correction processing circuit 13, a display processing circuit 14 that converts the corrected element output into a desired display format to image a subject, and operates the shutter 3, the driver circuit 10, the correction processing circuit 13, and the display processing circuit 14. A timing generation circuit 15 for supplying timing is included. The above-described components are housed in the housing 25.

In the infrared camera 40 shown in the first embodiment, the image pickup element 41 is connected to the element output level control circuit 42 for keeping the element output level constant.

FIG. 2 shows the element output level control circuit 4
2 is shown. The element output level control circuit 42 is connected to the DC power supply 9, and the element output level command value setting circuit 43 for setting the element output level of the image pickup element 41.
Is connected to a dummy pixel 44, which will be described later, and calculates the error between the element output level command value from the element output level command value setting circuit 43 and the input value from the dummy pixel 44, and integrates the calculated error. It includes an integrating circuit 46.

Further, FIG. 3 shows a schematic structure of the image pickup device 41. The actual image pickup device 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 device is shown in FIG. 3.

The image pickup device 41 includes a horizontal scanning circuit 26 for selecting pixels in the horizontal direction, a vertical scanning circuit 27 for selecting pixels in the vertical direction, a first transistor 28 for turning on / off a current to the pixels in the horizontal direction, and infrared rays. Detection pixel 29, second transistor 30 for turning on / off the current to the pixel in the vertical direction, third transistor 3 for controlling the current flowing through infrared detection pixel 29 and changing the element output level
Have one. Therefore, in the actual image pickup device 41, the first transistor 28 and the second transistor 30 corresponding to the number of rows and the number of columns of the plurality of infrared detection pixels 29 arranged in a matrix are present, and the horizontal scanning circuit 26 and The vertical scanning circuit 27 selects the predetermined first transistor 28 and second transistor 30 in the row and column to selectively select the infrared detection pixel 29.

In the image pickup device 41 of the first embodiment, the dummy pixel 44 that outputs a signal according to its own temperature regardless of the intensity of the incident infrared ray and the current flowing through the dummy pixel 44 are further controlled. , And includes a fourth transistor 47 for changing the element output level.

Here, the infrared detection pixel 29 has the same structure 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 void 34 formed therein. The bridge structure 33 is formed on the silicon substrate 35. Therefore, when infrared rays are incident on the infrared detection pixel 29 of the infrared detection element 32, the temperature of the infrared detection element 32 changes with respect to the silicon substrate 35 according to the incident amount. On the other hand, in the dummy pixel 44, as shown in FIG. 4, the infrared detection element 32, which is a thermal infrared detection element such as a bolometer or a diode, is supported by a solid bridge structure 48 having no void. . The bridge structure 48 is formed on the silicon substrate 35. Therefore, in the dummy pixel 44 portion, even if infrared rays are incident on the infrared detection element 32, the heat from the incident infrared rays immediately leaks to the silicon substrate 35 via the bridge structure 48, so that the infrared rays are substantially generated. It does not show any change, that is, it has no sensitivity to infrared rays.

As described above, the infrared detection pixel 29 and the dummy pixel 44 are arranged in the bridge structure 33 or the bridge structure 48.
It can be easily created by simply selecting one of the above.

In the image pickup device 41 thus constructed, a predetermined element is supplied from the driver circuit 10 to the infrared detection pixel 29 formed by the infrared detection element 32 supported by the bridge structure 33 having an air gap. It is selected by the horizontal scanning circuit 26 and the vertical scanning circuit 27 which operate based on the signal of the desired timing. By this selection, the current from the DC power supply 9 flows through 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 according to the amount of incident infrared light. On the other hand, the dummy pixel 44 formed by the infrared detection element 32 supported by the bridge structure 48 having no void is formed by the horizontal scanning circuit 26 and the vertical scanning circuit 2.
It receives a current from the DC power supply 9 completely independently of the circuit 7. At this time, the dummy pixel 44 always outputs a value based on its own temperature change, that is, a temperature change not affected by infrared rays, without any temperature change caused by infrared rays.

Next, the operation will be described. The infrared camera 40 includes an element temperature monitor 7, a thermoelectric element 8,
Since the temperature control circuit 11 is not provided, 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 the solid bridge structure 48 as shown in FIG. 4 and does not have the void like the infrared detection pixel 29 has, the temperature of the infrared detection element 32 becomes equal to that of the silicon substrate 35. , And outputs a signal according to the temperature of the dummy pixel 44 itself regardless of the intensity of incident infrared rays. Then, 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 integrating 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 integrating circuit 46, so that the element output level of the infrared detection pixel 29 is the element output level command value or It will always be kept constant in the vicinity.

As described above, according to the first embodiment, since the element output level is kept constant by continuous control regardless of the operating temperature of the image pickup element 41, the element temperature control and the element output level adjustment (initial adjustment) are performed. It becomes unnecessary and the work during assembly becomes easy. Further, it is possible to obtain an infrared camera in which the circuit scale and power consumption are reduced, and images are not interrupted in a wide temperature range.

In the image pickup device 41, the number of dummy pixels 44 and the positions of the dummy pixels 44 are arbitrary, and even one dummy pixel 44 can be made to function sufficiently. For example, as shown in FIG.
Predetermined positions around the infrared detection pixels 29 arranged in a matrix, for example, dummy pixels 44 are arranged at four corners, and the average value of signals according to the temperatures of a plurality (for example, four) dummy pixels 44 themselves is continuously measured. If the output level is controlled based on the average value calculated by the integration circuit 46, the operating state of the image sensor 41 can be recognized more accurately and the element output level can be automatically adjusted. Therefore, a better image can be obtained.

Embodiment 2. In the image pickup device 41, there may be a large difference in offset and sensitivity between pixels depending on the operating temperature depending on the characteristics of the material used for the infrared detection device 32. Similar to the conventional infrared camera 1 shown, element temperature control may be required in some cases. 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.

In the infrared camera 49, the first embodiment
The same members as those in the prior art will be described with the same reference numerals. Infrared optical system 2 that forms infrared light from the subject
And a shutter 3 that blocks infrared light from the infrared optical system 2.
And a window 4 arranged on the back surface side of the shutter 3 for transmitting 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 pickup element 41 as that in the first embodiment is arranged on the image plane of the infrared optical system 2. However, in the second embodiment, the image pickup element 41 is added to the image pickup element 41.
Element temperature monitor 7 for monitoring the temperature of the
The thermoelectric elements 8 that change the temperature of 1 are thermally connected to each other. The DC power supply 9 is also connected to the image pickup element 41.

Further, as the circuit configuration of the infrared camera 49, a driver circuit 10 connected to the image pickup element 41, a temperature control circuit 11 connected to the element temperature monitor 7 and the thermoelectric element 8 for controlling the temperature of the image pickup element 41 to be constant. An amplifier circuit 12 that amplifies the output of the image sensor 41, a correction processing circuit 13 that corrects the sensitivity, offset, and defect of the amplified element output, a display processing circuit 14 that converts the corrected element output into a desired display format, A timing generation circuit 15 for supplying operation timing to the shutter 3, 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 for setting the element control temperature. Element control temperature setting circuit 20 and second element control temperature for setting an element control temperature different from the first element control temperature setting circuit 20 The setting circuit 21, the temperature sensor 22 for monitoring the temperature inside the camera, the comparator 23 for switching the element control temperature changeover switch 19 when the output of the temperature sensor 22 exceeds a certain threshold, and the temperature switching threshold of the comparator 23 are set. A temperature switching threshold setting circuit 24 and the like are included. The above-described components are housed in the housing 25.

Also in the infrared camera 49 shown in the second embodiment, the element output level control circuit 42 for keeping the element output level of the image pickup element 41 constant is connected.
The element output level control circuit 42 has the same configuration as that of the first embodiment. The configuration of the image pickup element 41 is also the same as that of the first embodiment.

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 show the 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 those of 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. The level can be kept constant, and even when it is necessary to control the element temperature, it is not necessary to adjust the element output level setting for each operating temperature.

According to the second embodiment, there is a large variation in characteristics between pixels due to the operating temperature of the infrared detection element 32, and an assembly that does not require adjustment of element output level setting when conventional element temperature control is required is easy. It is possible to obtain the infrared camera 49 which can be used for

[0040]

As described above, according to the present invention, an infrared detecting pixel having sensitivity to an incident infrared ray and a pixel arranged in the vicinity of the infrared detecting pixel and having the same electric characteristics are incident. A dummy pixel that continuously outputs a signal according to its own temperature without waiting for sensitivity to infrared rays,
And an image sensor that outputs a signal according to the intensity of incident infrared light, and an element output level that controls the output level of the image sensor to be constant based on the outputs from the infrared detection pixel and the dummy pixel. By configuring the infrared camera with the control circuit, the element output level is kept constant regardless of the operating temperature of the image sensor, so element temperature control and element output level adjustment are not required, facilitating assembly work. In addition, it is possible to obtain an infrared camera in which the circuit scale and power consumption are reduced and images are not interrupted in a wide temperature range.

Further, according to the present invention, in the above-mentioned structure, the dummy pixel supports the infrared detection pixel with a solid support, thereby leaking a temperature change due to infrared rays through the support, thereby improving sensitivity to infrared. Since it is suppressed, the dummy pixel can be formed with a simple structure, and the infrared detection pixel and the dummy pixel can be easily formed separately.

Further, according to the present invention, in the above structure, a plurality of dummy pixels are provided, and the average value of the signals corresponding to the temperatures of the plurality of dummy pixels themselves is continuously output to control the output level. As a result, the output level of the image sensor can be made more constant.

Further, according to the present invention, in the above structure, the element output level control circuit integrates an error between the output signal of the dummy pixel and the preset element output level command value, and outputs the element output level in the image pickup element. Since the element output level is made constant by feeding back to the control means for controlling the element, it is possible to control the element output level in real time with a simple structure.

Further, according to the present invention, in the above configuration, a thermal control element for supplying or cooling heat to the image pickup element according to the supplied power, a temperature monitor for monitoring the temperature of the image pickup element, and a plurality of element control temperatures. The element control temperature setting circuit that sets the temperature, the temperature sensor that monitors the camera internal temperature, the element control temperature changeover switch that switches the output of the element temperature setting circuit according to the output of the temperature sensor, and the element temperature changeover switch. When a temperature control circuit that supplies electric power to the thermal control element to control the temperature of the image pickup element to a different temperature is used, the characteristic variation between pixels due to the operating temperature of the image pickup element is large and the element temperature control is required. However, due to the operation of the element output level control circuit using the dummy element, it is good without adjusting the element output level setting for each operating temperature. It is possible to obtain an infrared camera operating.

[Brief description of drawings]

FIG. 1 is a block diagram illustrating a schematic configuration of an infrared camera according to a first embodiment 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 the first embodiment of the present invention.

FIG. 3 is an explanatory diagram illustrating a structure of a dummy pixel of the infrared camera according to the first embodiment of the present invention.

FIG. 4 is a structural diagram showing a structure of a dummy pixel in the first embodiment of the infrared camera according to the present invention.

FIG. 5 is a structural diagram showing a structure in the case where a plurality of dummy pixels are arranged in the first embodiment of the infrared camera according to the present invention.

FIG. 6 is a block diagram illustrating a schematic configuration of an infrared camera according to a second embodiment 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 a 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]

1 infrared camera, 2 infrared optics, 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.

Continued front page    F-term (reference) 2G065 AA11 AB02 BA12 BA34 BA40                       BC03 BC19 CA21 DA18                 5C022 AA15 AB13 AB20 AB40 AC42                       AC52                 5C024 AX06 CY46 GX08 HX18 HX29                       HX31

Claims (5)

[Claims] 1. An infrared camera for detecting a radiation amount of infrared rays according to a temperature change to form a subject image, the infrared detecting pixel having sensitivity to incident infrared rays,
A pixel which has a similar electrical characteristic and is arranged in the vicinity of the infrared detection pixel, and which includes a dummy pixel which continuously outputs a signal according to its own temperature without waiting for sensitivity to the incident infrared light An image sensor that outputs a signal according to the intensity of infrared rays; and an element output level control circuit that controls the output level of the image sensor to be constant based on the outputs from the infrared detection pixels and the dummy pixels, Infrared camera characterized by including. 2. The dummy pixel supports the infrared detection pixel with a solid support, and leaks a temperature change due to infrared rays through the support,
The infrared camera according to claim 1, wherein sensitivity to infrared rays is suppressed. 3. The image pickup device has a plurality of dummy pixels, and continuously outputs an average value of a signal according to the temperature of the plurality of dummy pixels to control an output level. The infrared camera according to claim 1 or 2. 4. 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 feeds it back to a control means for controlling an element output level in the image pickup element. 2. The element output level is made constant by performing the above operation.
4. The infrared camera according to claim 3. 5. A thermal control element for supplying or cooling heat to the image pickup element in accordance with the supply power, a temperature monitor for monitoring the temperature of the image pickup element, and 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 changeover switch that switches the output of the element control temperature setting circuit according to the output of the temperature sensor; and a temperature selected by the element control temperature changeover switch. An infrared camera according to claim 1, further comprising: a temperature control circuit that supplies electric power to the thermal control element to control the temperature of the image pickup element.