JP3495571B2 - Uncooled infrared 2D sensor camera with shading correction function - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to the field of technology for correcting shading in an infrared camera using an infrared two-dimensional sensor.

[0002]

2. Description of the Related Art In an infrared camera, the amount of infrared energy that is incident on a two-dimensional sensor due to stray light inside the camera casing, regardless of the object to be measured, increases from the center to the periphery when the environmental temperature is high. When the ambient temperature is low, the amount of energy increases, and when the ambient temperature is low, the amount of energy decreases from the center to the periphery, which is a so-called shading phenomenon (temperature gradient). This is particularly noticeable in uncooled infrared cameras. If such a temperature gradient should not exist, it would not be possible to accurately measure the temperature from the infrared image. Therefore, the following circuit has been conventionally used to correct the effect of this shading.

FIG. 4 is a block diagram showing the configuration of an embodiment of a conventional infrared camera. Infrared rays from the outside world are condensed by a combination lens (not shown) provided with a shutter that can be opened and closed at the position of the optical pupil. When the shutter is opened, the collected infrared rays form an image on the surface of the infrared two-dimensional sensor 1. From the infrared two-dimensional sensor 1, an electric signal corresponding to the infrared intensity is extracted for each pixel by a constant scan (for example, raster scan). The infrared image signal thus taken out is amplified by the amplifier 2 to a level required for subsequent processing. The amplified signal is converted by the A / D converter 3 into digital data having a bit number satisfying the required gradation. The obtained digital data is input to one of the input terminals of the subtractor 4 for reducing the influence of shading, and is output to the TV scan conversion memories 9a and 10a in a form in which the influence of shading is removed.

On the other hand, the shading correction memory 11 is connected so as to be able to store the output of the subtractor 4, and is also connected so that the stored signal can be read and input to the other input terminal of the subtractor 4. ing. The action is
The output of the A / D converter 3 when the shutter is closed is stored in the shading correction memory 11 via the subtracter 4 for one screen. At this time, since the reading from the shading correction memory 11 is not performed,
Although the subtracter 4 performs the subtraction, the input from the A / D converter 3 is output as it is and the shading correction memory 1
1 is stored for each pixel. Thus, the stored data is the data of the shading thermal image due to the stray light in the lens and the housing after the shutter.

On the other hand, the thermal image formed on the infrared two-dimensional sensor 1 when the shutter is opened to collect infrared rays from the outside world is obtained by adding infrared rays from the outside world and shading. It is in the state.
Therefore, in order to obtain a thermal image with only infrared rays from the outside, it is sufficient to subtract the shading thermal image portion from the thermal image formed on the infrared two-dimensional sensor.

Therefore, the shading thermal image data of the shading correction memory 11 is read out and input to the other input terminal of the subtractor 4 and subtracted from the input signal from the A / D converter 3 for each corresponding pixel, whereby the shading Thermal image data can be obtained only by infrared rays from the outside world without influence.

[0007]

However, in such a conventional circuit, since the TV scan conversion memory carries out the TV scan conversion, it is usually constituted by the two frame memories 9a and 10a as described above, and is alternately arranged. One is used for reading and one is used for writing. As described above, the memory for storing the thermal image includes the shading correction memory 11 and the TV scan conversion memory 9.
Since three memories a and 10a are required and the number of memory elements is required for the number of memories, there is a problem that it becomes a major obstacle to downsizing the device and reducing power consumption. The present invention has been made to solve the above problems, and an object thereof is to provide an uncooled infrared two-dimensional sensor camera with a shading correction function that can reduce the number of memory elements.

[0008]

An uncooled infrared two-dimensional sensor camera with a shading correction function of the present invention is characterized by having the following configuration. (B) Optical system having an opening / closing mechanism for condensing / shielding infrared rays (b) Two-dimensional sensor for forming an infrared image by the optical system (c) Analog electric signal output by image scanning to the two-dimensional sensor A / D converter for converting each pixel into digital data (d) Digital data from the A / D converter is used as input data at one of the input ends and data input to the other input end. Subtractor for performing subtraction between (e) After storing the data for one frame of the output of the A / D converter when the infrared light is shielded by closing the opening / closing mechanism, after the data is opened. , the stored data, rank in one of system a shading correction memory (vi) the system a shading correction memory is read out to match the pixel positions of data input to the input terminal of said subtractor Has been
A when infrared rays are blocked by closing the opening / closing mechanism
The data for 1 frame output from the / D converter is transferred
It is transferred under control of the road and stored, and this opening / closing mechanism opens.
Input to one of the input terminals of the subtractor
Read out by matching the pixel position of the data
B system shading correction memory ( G ) Read from the A system shading correction memory
Data to be read and the B system shading correction memory
Received data may be controlled by the transfer circuit described later.
Send one of the data to the other input of the subtractor
Selection circuit (h) Transfer circuit for controlling the transfer and selection (i) A circuit for storing the output of the subtracter for each screen, and an A-system frame memory including the same elements as the A-system shading correction memory ( E) A B-system frame memory for storing the output of the subtractor in units of one screen, and including the same element as the B-system shading correction memory

In the uncooled infrared two-dimensional sensor camera with shading correction function, when the infrared light is shielded by closing the opening / closing mechanism instead of the subtractor, digital data from the A / D converter is used. Is the input data of one of the input terminals, the average value is calculated with the data input to the other input terminal, and the subtraction is performed when infrared rays are collected by opening this opening / closing mechanism. And storing the first one frame of digital data from the A / D converter when the opening / closing mechanism is closed, instead of the A-system shading correction memory, and storing the stored data. Is read out in conformity with the pixel position of the data input to one of the input terminals of the arithmetic unit, and is input to the other input terminal of the arithmetic unit. Input, and finally the average value calculated by this arithmetic unit is stored for one frame, and after that, the stored data is input to one of the input terminals of the arithmetic unit. It is characterized by comprising an A-system shading correction memory which is read out in conformity with the pixel position of the stored data.

[0010]

BEST MODE FOR CARRYING OUT THE INVENTION In the embodiment of the present invention, a combination lens having a shutter whose opening / closing control is easily performed from the outside is used at an optical pupil position, and the shutter is closed to block infrared rays through the lens. Pixel scanning of an infrared two-dimensional sensor in the state of being affected by shading due to stray light is performed, and the obtained signal is stored in a shading correction memory for each pixel, and then the shutter is opened to generate an infrared image from the outside as an infrared image. An image is formed on a two-dimensional sensor, and pixel scanning is performed on this to extract a signal for each pixel. From this signal, the signal of the corresponding pixel stored in the shading correction memory is read out and subtracted. The effect of shading is removed by subtracting with a calculator.

As described above, the shutter is closed and stored in the shading correction memory, that is, the updating of the shading correction memory may be automatically performed at a predetermined fixed cycle, or the time may be changed. It may be performed when the temperature change with the passage of time exceeds a predetermined value. This may also be done by operator observation or automatically.

[0012]

Embodiments of the infrared camera of the present invention will be described below in detail with reference to the drawings. FIG. 1 is a block diagram showing a configuration of an embodiment of an infrared camera of the present invention, FIG. 2 is a timing chart showing an operation state of each pixel of the infrared camera, and FIG. 3 is a timing chart showing an operation state of each frame. Is. As shown in FIG. 1, this infrared camera basically comprises an infrared two-dimensional sensor 1, an amplifier 2 and an A
/ D converter 3, arithmetic unit 4, sensor data write control circuit 5, TV scan data read control circuit 6, shading thermal image data generation timing control circuit 7, shading thermal image data memory transfer circuit 8, TV scan conversion memory 9 10, a selection circuit 11, 13 to 20, and a block of a register 12. TV with 2 channels
In the scan conversion memories 9 and 10, the memory 9 side is A
The system memory and the memory 10 side will be referred to as B system memory, the shading correction data will be referred to as shading thermal image data, and the data after shading correction will be referred to as thermal image data.

Next, the role of each block will be described. The infrared two-dimensional sensor 1 has an opening / closing mechanism (not shown), detects infrared rays formed by an optical system that collects / shields infrared rays, and converts the infrared rays into an electric signal 201 corresponding to the infrared intensity for each pixel by constant scanning. The amplifier 2 amplifies the electric signal 201 to a necessary level of the electric signal 202, and the A / D converter 3 converts the electric signal 202 into the first digital data 203 having the number of bits satisfying the required gradation. The scanning is performed by a line sync signal 104, which is a horizontal scan timing signal, and a frame sync signal 105, which is a vertical scan timing signal, which are generated by using a frame start signal 103 from a TV scan data read control circuit 6 described later as a trigger signal. .

The computing unit 4 is a computing unit that calculates shading thermal image data and thermal image data, and operates as an average value calculation circuit when the shading thermal image data is calculated by closing the opening / closing mechanism and blocking infrared rays. LA from the first digital data 203 and the register 12 described later
/ B shading thermal image data 212 average value,
When the opening / closing mechanism is opened to calculate the thermal image data, it operates as a subtractor, and the first digital data 203 is used for LA
/ B shading thermal image data 212 has a second subtraction value
It is output as digital data 204 .

The sensor data writing control circuit 5 is a control unit of the A system memory 9 and the B system memory 10 at the time of shading thermal image data and thermal image data writing, and is a line sync signal 104, a frame sync signal 105, and a later-described signal. Shading thermal image data write signal 106 from the shading thermal image data generation timing control circuit 7
Based on the above, the sensor system write / read control signal 108 necessary for storing the data in the A system memory 9 and the B system memory 10, and the first one frame when the shading thermal image data is written. The clear signal 107 that sets the period LA / B shading thermal image data 212 to “0” is generated.
This is because when calculating the shading thermal image data, the thermal images of the frame period previously designated by the arithmetic unit 4 are added,
This is because the average value is obtained by dividing by the number of frames and the result is used as shading thermal image data.

The TV scan data read control circuit 6 includes
The frame start signal 103 and the TV synchronization signal of the infrared two-dimensional sensor 1 are generated by the control units of the A system memory 9 and the B system memory 10 at the time of reading the thermal image data in the TV system, and the A synchronization signal is generated based on the TV synchronization signal. A TV read control signal 109 is generated in accordance with the TV timing required to read the thermal image data from the system memory 9 and the B system memory 10.
Also, each time the frame start signal 101 is repeated, the A system TV read mode signal 110 and the B system TV for alternately setting the A system memory 9 and the B system memory 10 to the read / write mode.
The read control signal 111 is generated. When this read / write mode switching receives a freeze signal 102 described later, the change of the write / read mode is stopped at that point.

The shading thermal image data generation timing control circuit 7 is an overall control unit for shading thermal image data generation, and receives the shading correction start signal 101 to avoid unnaturalness of thermal image display during shading thermal image data generation. In order to do so, a freeze signal 102 for stopping the updating of the memory of the system that is not generating shading thermal image data, a shading thermal image data write signal 106 for writing shading thermal image data,
And a transfer start signal 113 for starting the transfer of the shading thermal image data written in one system to the other system.
To generate. The freeze period of the freeze signal 102 ends when it receives the transfer end signal 121 from the shading thermal image data memory transfer circuit 8 described later.

The shading thermal image data memory transfer circuit 8 is a transfer control unit for the shading thermal image data between the A-system memory 9 and the B-system memory 10, and the transfer start signal 1
A-system transfer control signal 115 and B-system transfer control signal 1 which are control signals necessary for transferring the shading thermal image data between the A-system memory 9 and the B-system memory 10 based on 13.
20 to generate the A-system write data selection signal 118 and the B-system write data selection signal 123 which are control signals necessary for selecting the write data, and also generate the second A / B shading thermal image data. Shading thermal image data 205 and 208 are generated based on 214. The transfer mode signal 116 is generated during the transfer, and the transfer end signal 121 is generated when the transfer is completed.

The A-system memory 9 and the B-system memory 10 each include a thermal image data area and a shading thermal image data area, and store the thermal image data and the shading thermal image data in units of frames. In the A system memory 9, the use area is determined by the A system memory control signal 117 and the A system write data selection signal 118,
When shading thermal image data is written or when shading thermal image data is transferred, it is written in or read from the shading thermal image data area, when shading correction is performed, it is written in the thermal image data area, and when thermal image data is read, the thermal image data area Read from. In the B-system memory 10, the use area is determined by the B-system memory control signal 122 and the B-system write data selection signal 123, and the shading thermal image data area is written at the time of shading thermal image data writing or shading thermal image data transfer. Or read out,
The data is written in the thermal image data area at the time of shading correction, and is read from the thermal image data area at the time of reading the thermal image data.

The selection circuit 11 is a selection circuit for determining the A-system write data which is the write data to the A-system memory 9, and the shading thermal image data 205 when the shading thermal image data is transferred by the A-system write data selection signal 118. Other than that, the second digital data 204 is selected and output as A-system write digital data 206. The register 12 supplies the LA / B shading thermal image data 212 to the arithmetic unit 4. When writing the shading thermal image data, it is set to "0" by the clear signal 107 in the first one frame.

The selection circuit 13 is a first selection circuit that determines the control signal of the A system memory 9, and selects either the sensor system write / read control signal 108 or the TV system read control signal 109. , A system TV read mode signal 110 selects TV system read control signal 109 in the TV read mode, and sensor system write / read control signal 108 otherwise.
Is selected and output as the A-system first write / read control signal 114. The selection circuit 14 is a second selection circuit that determines the control signal of the A system memory 9, and selects either the A system first write / read control signal 114 or the A system transfer control signal 115. By the transfer mode signal 116, the A-system transfer control signal 115 is selected at the time of shading thermal image data transfer, and otherwise the A-system first write / read control signal 114 is selected and output as the A-system memory control signal 117. .

The selection circuit 15 is a selection circuit for selecting one of the A system shading thermal image data and the B system shading thermal image data.
10 and shading thermal image writing signal 106
System A memory 9 when writing shading thermal image data
When the B system shading thermal image data is written, the A system read data 207 from B system read data 210 from the B system memory 10 is selected and output as the first A / B shading thermal image data 211.

The selection circuit 16 is a selector circuit for determining the transfer source shading thermal image data, A system read data 2
07 or B system read data 210 is selected. The A system TV read mode signal 110 and the transfer mode signal 116 are used to select the A system read data 207 when transferring from the A system memory 9 and the B system. At the time of transfer from the memory 10, the B-system read data 210 is selected and output as the second A / B shading thermal image data 214.

The selection circuit 17 is a circuit for selecting one of the A system read data 207 from the A system memory 9 and the B system read data 210 from the B system memory 10. When the system TV is read, the system A read data 207 is selected, and otherwise, the system B read data 210 is selected.
Is selected and output as thermal image data 213. The selection circuit 18 is a selection circuit that determines the B-system write data that is the write data to the B-system memory 10, and selects the shading thermal image data 208 at the time of transferring the shading thermal image data by the B-system write data selection signal 123. Other than that, the second digital data 204 is selected and output as the B-system write digital data 209.

The selection circuit 19 is a first selection circuit for determining the control signal of the B system memory 10, and selects either the sensor system write / read control signal 108 or the TV system read control signal 109. , B system TV read mode signal 111 selects TV system read control signal 109 in the TV read mode, and sensor system write / read control signal 108 otherwise.
Is output as the B-system first write / read control signal 119.

The selection circuit 20 is a second selection circuit that determines a control signal for the B-system memory 10, and selects one of the B-system first write / read control signal 119 and the B-system transfer control signal 120. The transfer mode signal 116 causes the B-system transfer control signal 1 when shading thermal image data is transferred.
20 is selected and the other B-system first write / read control signal 119 is selected and output as the B-system memory control signal 122.

In such an infrared camera, first, shading thermal image data is written in the shading thermal image area of either one of the A system memory and the B system memory, and then the shading thermal image data is stored in the memory of another system. The shading thermal image data of both systems is made the same. Next, based on this shading thermal image data, the thermal image data is written in the thermal image data area of the memory of one system, the thermal image data is read from the thermal image data area of the memory of the other system, and is displayed (not shown). Display on the device. In this way, shading correction is realized. As described above, the reason why the shading thermal image data is transferred from one system to the other system and the shading thermal image data is not generated for each system separately is that the systems are alternately set to the thermal image writing / reading mode. This is because, if the shading thermal image data of each system is different at that time, the same thermal image data will be different for each system, which will give a feeling of strangeness when displayed.

As described above, the operation modes include the following four modes. (1) Shading thermal image data generation mode (2) Shading thermal image data transfer mode (3) Thermal image data writing mode (4) Thermal image data reading mode

FIG. 2 shows an A system memory 9 or a B system memory 10.
FIG. 3 is a diagram for explaining the writing / reading control of each of the pixels in units of pixels, which is a component of the line sync signal 104 of the infrared sensor camera 1 on the time axis, and FIG. It is a figure explaining in the signal 105 unit. In FIG. 2, (A) is a line sync signal 104 of the infrared two-dimensional sensor 1, (B) is an address AD in pixel units updated for each pixel unit from the infrared two-dimensional sensor 1, (C) and (D). Indicates the read / write state of the A-system memory 9 or B-system memory 10,
(C) is for writing thermal image data, and (D) is for generating shading thermal image data.

In FIG. 3, (A) is a frame sync signal 105 of the infrared two-dimensional sensor 1, (B) is an operating state of the A system memory 9, (C) is an operating state of the B system memory 10,
(D) is a shading correction start signal 101, (E) is a freeze signal 102 that prohibits rewriting of the memory of one system when writing shading thermal image data, and (F) is the first frame when writing shading thermal image data. Clear signal 107 for holding the data of 0 to "0", (G) is a shading thermal image data write signal 106, and (H) is a transfer start signal for controlling the start of transfer of the shading thermal image data to the memory of the other system. It is 113 .

As shown in FIGS. 3B and 3C, the A system memory 9 and the B system memory 10 alternate during the thermal image data writing, which is a normal operation other than the shading thermal image data writing. The thermal image data is written in one of them, the thermal image is read out from the other one, and the thermal image is displayed on a monitor (not shown). As shown in FIG. 2C, the operation of the infrared two-dimensional sensor 1 at the horizontal timing during the normal operation is as shown in FIG. 2C, in which the shading correction data is read from the TV scan conversion memory in the first half of each pixel and then the pixel at the same position is read. The difference from the data is taken and the result is written in the thermal image area of the TV scan conversion memory. The shading correction start signal 101 is generated by monitoring the environmental temperature change as described above, and every time when the temperature exceeds a predetermined constant temperature, at a predetermined constant time, or when the user arbitrarily presses a trigger button. Is generated.

When the shading correction start control signal 101 is received by the shading correction timing control circuit 7, the shading thermal image data write signal 106 and the freeze signal 102 are generated. Upon receiving the freeze signal 102, the TV scan data read control circuit 6 makes either one of the two systems of TV scan conversion memories read-only and the other one write-only.

Now, the shading thermal image data writing operation will be described assuming that the shading correction start signal 101 is generated at the timing (1) shown in FIG. 3D. The shading thermal image data generation timing control circuit 7 receives the shading correction start signal 101, receives the freeze signal 102 at the timing shown in (2) of FIG. 3E, and the clear signal 107 at the timing shown in (3) of FIG. And shading thermal image data write signal 1
06 is generated. Upon receiving the freeze signal 102, the TV scan data read control circuit 6 puts the A system memory 9 in the write mode and the B system memory 10 as shown in FIGS. 3 (B) and 3 (C).
To the read mode.

Since the A system memory 9 is in the writing mode, the sensor system write / read control signal 108 by the selection circuits 13 and 14 is used as the A system memory control signal 117.
Is input, and as the A-system write digital data 206, the second digital data 204 obtained from the calculator 4 by the selection circuit 11 is input. Further, the selection circuit 15 inputs the shading thermal image data of the A system memory 9 into the register 12 as the first A / B shading thermal image data 211, and the clear signal 107 becomes valid first when writing the shading thermal image data. Except for one frame, the LA / B shading thermal image data 212 is directly supplied to the arithmetic unit 4. At this time, the arithmetic unit 4 operates as an average value calculation circuit as described above, calculates the average value between the first digital data 203 and the LA / B shading thermal image data 212, and outputs it as the second digital data 204. . By doing so, the shading thermal image data is stored in the shading correction data area of the A system memory 9. Note that the shading thermal image data write signal 106 is output for two frames in FIG. 3G. In the present embodiment, the shading thermal image data is calculated by integrating for two frames and taking an average value. This is because I decided.

At this time, as for the operation of the horizontal timing signal, as shown in FIG. 2D, the shading thermal image data of the A-system memory 9 is read in the first half of each pixel, and the infrared ray two-dimensional is calculated by the arithmetic unit 4 in the latter half. The calculation result of the detection data from the sensor 1 and the shading thermal image normal data is written in the shading correction data area of the A system memory 9.

Next, the transfer of shading thermal image data will be described. When the writing of the shading thermal image data is completed at the timing shown in (4) of FIG.
At that time, the transfer start signal 113 shown in FIG. 3H is output. As described above, when the transfer start signal 113 is received, the shading thermal image data memory transfer circuit 8 generates a signal necessary for transfer. Therefore, the A system memory control signal 117 of the A system memory 9 is the A system transfer control signal. 115 is selected, shading thermal image data is selected as the A-system read data 207, and the B-system transfer control signal 120 is selected as the B-system memory control signal 122 of the B-system memory 10.
Is selected, and the shading thermal image data 208 is selected as the B-system write digital data 209. Also L
As the A / B shading thermal image data 212, the shading thermal image data is selected as the A-system read data 207. In this way, the A-system shading thermal image data stored in the A-system memory 9 is transferred to the shading thermal image data area of the B-system memory 10.

Next, generation of thermal image data will be described. Since the A system memory 9 is in the write mode,
The A-system control signal 117, the sensor Keishokomi / read control signal 108 is inputted by the selection circuits 13, 14, A system
As the write digital data 206, the second digital data 204 obtained from the calculator 4 by the selection circuit 11 is input. Further, the selection circuit 15 causes the register 12 to store the shading thermal image data of the A system memory 9 in the first A
/ B shading thermal image data 211 is input as it is, LA / B shading thermal image data 21
2 is supplied to the calculator 4. At this time, the arithmetic unit 4 operates as a subtractor as described above, and the first digital data 203 and the LA / B shading thermal image data 212 are processed.
The subtracted value between is calculated and output as the second digital data 204. By doing so, the thermal image data is stored in the thermal image data area of the A system memory 9.

Next, reading of thermal image data will be described. Since the B-system memory 10 is in the read mode, the B-system memory control signal 122 includes the selection circuit 19,
The TV system read control signal 109 is input by 20 and
As the B-system read data 210, thermal image data is read from the thermal image data area. This thermal image data is selected by the selection circuit 1.
It is selected at 7 and displayed on a display device (not shown).

The operation of writing the shading thermal image data in the A system memory 9 and then transferring the shading thermal image data to the B system memory 10 and then obtaining the thermal image data has been described above. Also when writing shading infrared image data to
The description will be omitted because the signals only change accordingly.

In this embodiment, the infrared data from the infrared two-dimensional sensor 1 is averaged over two frames to calculate the shading thermal image data, but the number of frames for which the average value is calculated is limited to this. However, it is possible to increase or decrease as appropriate. Further, it is also a useful means that the data from the infrared two-dimensional sensor 1 is used as it is as shading thermal image data without averaging, so that the arithmetic unit 4 is used only as a subtractor and the circuit has a simple configuration. Is.

[0041]

According to the present invention, as described above,
One TV scan conversion memory is divided into a thermal image data area and a shading thermal image data area of the object, and two memories are provided. Since scan conversion is also possible, there is no need to provide three memory elements for each function, the number of memory elements can be reduced by one, and the peripheral circuit of the memory can be simplified by using FPGA or GA. Since the device can be configured with one element, the device can be downsized and the power consumption can be reduced, and it is possible to provide an uncooled infrared two-dimensional camera suitable for a portable type. It was

[Brief description of drawings]

FIG. 1 is a block diagram showing a configuration of an embodiment of an uncooled infrared two-dimensional sensor camera with a shading correction function of the present invention.

FIG. 2 is a timing chart showing an operation in pixel units of the shading correction circuit of the present invention.

FIG. 3 is a timing chart showing the operation of the shading correction circuit of the present invention in units of frames.

FIG. 4 is a block diagram showing a configuration of an example of a conventional uncooled infrared two-dimensional sensor camera with a shading correction function.

[Explanation of symbols]

1 infrared two-dimensional sensor 2 amplifier 3 A / D converter 4 arithmetic unit 5 sensor data write control circuit 6 TV scan data read control circuit 7 shading thermal image data generation timing control circuit 8 shading data memory transfer circuit 9, 10 TV scan Conversion memories 11, 13, 14, 15, 16, 17, 18, 19, 2
0 selection circuit 12 registers

Claims (2)

(57) [Claims] 1. An uncooled infrared two-dimensional sensor camera with a shading correction function, comprising the following components. (B) Optical system having an opening / closing mechanism for condensing / shielding infrared rays (b) Two-dimensional sensor for forming an infrared image by the optical system (c) Analog electric signal output by image scanning to the two-dimensional sensor A / D converter for converting each pixel into digital data (d) Digital data from the A / D converter is used as input data at one of the input ends and data input to the other input end. Subtractor for performing subtraction between (e) Data of one frame output of the A / D converter when infrared rays are shielded by closing the opening / closing mechanism is stored , and then opened. , the stored data, rank in one of system a shading correction memory (vi) the system a shading correction memory is read out to match the pixel positions of data input to the input terminal of said subtractor Has been
A when infrared rays are blocked by closing the opening / closing mechanism
The data for one frame output from the D / D converter is transferred later.
It is transferred under control of the road and stored, and this opening / closing mechanism opens.
Input to one of the input terminals of the subtractor
Read out by matching the pixel position of the data
B system shading correction memory ( G ) Read from the A system shading correction memory
Data to be read and the B system shading correction memory
Received data may be controlled by the transfer circuit described later.
Send one of the data to the other input of the subtractor
Selection circuit (h) Transfer circuit for controlling the transfer and selection (i) A circuit for storing the output of the subtracter for each screen, and an A-system frame memory including the same elements as the A-system shading correction memory ( E) A B-system frame memory for storing the output of the subtractor in units of one screen, and including the same element as the B-system shading correction memory 2. When the infrared rays are shielded by closing the opening / closing mechanism instead of the subtractor, the A
The digital data from the D / D converter is used as the input data of one of the input ends, the average value is calculated with the data input to the other input end, and infrared rays are collected by opening this opening / closing mechanism. When the open / close mechanism is closed, instead of the A-system shading correction memory, the first one frame of digital data from the A / D converter is stored. Store and
The stored data is read out by matching the pixel position of the data being input to either one of <br/> input of the arithmetic unit is input to the other input terminal of the arithmetic unit, Finally, the average value calculated by this arithmetic unit is stored for one frame, and after that, the stored data is input to one of the input terminals of the arithmetic unit. The uncooled infrared two-dimensional sensor camera with a shading correction function according to claim 1, further comprising an A-system shading correction memory which is read out in conformity with a pixel position of data.