JPH095168A - Infrared video apparatus - Google Patents

Abstract

PURPOSE: To provide an infrared video apparatus with higher reliability of quality of picture by making the correction of variations in responsibility and variations in dark current. CONSTITUTION: This video apparatus is provided with an infrared detector 1 having infrared detectors 3 cooled down to a specified low temperature, a mirror 20 into which a reflection surface is inserted facing the infrared detector 3 to cut an incident optical path in front of the infrared detector 1, a drive means 100 to insert the mirror 20 into the incident optical path and a processing circuit to correct outputs of the individual infrared detectors 3 evenly in a state that the incident optical path is cut by the mirror 20.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an infrared imager, and more particularly to an infrared imager in which variations in dark current component are eliminated.

As shown in FIG. 8, the infrared imager is
The infrared ray radiated by the object is converted into parallel rays by the objective lens system 7 and converged, and the infrared ray detecting element 3 mounted on the infrared ray detector 1 is provided.
Infrared rays are detected by projecting on the light receiving surface of, and the photocurrent output from the infrared ray detecting element 3 is amplified by the amplifier circuit 11 and the video circuit 12
The image is displayed on the CRT monitor 13 through the above.

The infrared detecting elements 3 are arranged on the surface of the substrate 2 made of sapphire or the like in the longitudinal direction at an equal pitch. Each infrared detection element 3 is composed of a light receiving part formed of a square piece (50 μm to 100 μm on one side, about 10 μm in thickness) of HgCdTe, etc., and an output conductor pattern is provided on each side edge of the light receiving part facing each other. It is provided.

The substrate 2 is mounted on a base 4 containing a cooler 5 such as liquid nitrogen and a Joule-Thomson cooler, and the infrared detection element 3 is cooled to an extremely low temperature (around 80K) to obtain the energy at room temperature. The influence of KT (K is Boltzmann's constant and T is absolute temperature) is eliminated.

Further, in order to improve the spatial resolution of the infrared detector 1, it is necessary to set the viewing angle of the infrared detecting element 3 to a predetermined value to prevent stray light. For that purpose, a cold aperture 6 is mounted on the base 4 so as to surround the arrayed infrared detection elements 3.

[0006]

2. Description of the Related Art Due to variations in manufacturing quality, there are variations in responsivity between infrared detection elements of infrared detectors, and the photocurrent output by each infrared detection element upon receiving infrared rays is detected by parallel infrared detection. It is non-uniform between elements.

Therefore, if the infrared imaging device is used without correcting this variation in responsivity,
The reliability of the obtained image is reduced. For this reason, before or during acquisition of infrared rays, a temperature reference plate having a mechanically uniform infrared emitting surface is inserted in the incident optical path of infrared rays in a short time, and the photocurrent of each infrared detection element is measured, It is required to correct the steady-state deviation of the infrared detection element.

On the other hand, even if infrared rays radiated by an object do not enter the infrared detecting element, a current flowing under a reverse bias, a so-called dark current, flows through the infrared detecting element. This photocurrent also varies among the infrared detection elements arranged in parallel.

Therefore, before or during acquisition of infrared rays, uniform infrared rays serving as a temperature reference are incident on the infrared detection elements to correct the dark current between the infrared detection elements, and on the corrected photocurrent, It is necessary to superimpose the infrared photocurrent emitted from the object.

Conventionally, a uniform temperature reference plate (for example, a metal plate having a temperature equal to room temperature) is manually inserted into the front surface of the objective lens system immediately before or during the reception of infrared rays to block the incident optical path. The photocurrent of each infrared detection element is measured, and the steady-state deviation of the infrared detection element is automatically corrected by the signal processing circuit provided in the infrared imaging device.

Alternatively, immediately before or during the reception of the infrared rays, the light receiving port of the infrared detector is directed toward the sky, the temperature of the sky is used as a reference, and the photocurrent of each infrared detection element is measured. The deviation is automatically corrected by the processing circuit provided in the infrared imager.

[0012]

A means for correcting the steady deviation by inserting a temperature reference plate in front of the objective lens system to block the incident optical path, and a steady deviation based on the temperature of the sky with the light receiving port facing the sky. Responsiveness can also be corrected by means of means for correcting.

However, since the infrared energy radiated by the temperature reference plate or the infrared energy from the sky is incident on the infrared detector, there is a problem that the variation of the dark current component cannot be corrected.

Further, there is a problem that the means for inserting the temperature reference plate in front of the objective lens system cannot be applied to the infrared imaging device mounted on the flying object. On the other hand, the means for pointing the light receiving port of the infrared detector to the sky and using the temperature of the sky as a reference has the problem that the temperature of the sky is not uniform when there is cloud, and the accuracy of the responsivity correction is low. was there.

The present invention has been made in view of the above points, and provides an infrared image device having a high reliability of image quality by performing the correction of the variation of the responsivity and the correction of the variation of the dark current. The purpose is to do.

[0016]

In order to achieve the above object, the present invention provides an infrared detector 1 in which infrared detection elements 3 cooled to a predetermined low temperature are arranged in parallel, as shown in FIG.
A mirror 20 whose reflective surface is inserted so as to face the infrared detection element 3 so as to block the incident optical path on the front surface of the infrared detector 1;
Driving means 100 for inserting the mirror 20 into the incident optical path for a predetermined time
And a processing circuit 14 for uniformly correcting the output of each infrared detection element 3 with the mirror 20 blocking the incident optical path.

Alternatively, the incident optical path A to the infrared detecting element 3
A concave mirror 21 is used as a mirror which is inserted in the front surface of the infrared detector 1 with the reflection surface on the infrared detecting element side so as to block the light.

The above-mentioned driving means for driving the mirror has the mirror 20 (or the concave mirror 21) mounted on the tip thereof, and swings in a plane perpendicular to the incident optical path about the spindle provided on the stand. It is assumed that an arm and a swing motion imparting mechanism that drives the arm so that the mirror blocks the incident optical path A at one inversion point of the swing motion of the arm and stops for a predetermined time.

As shown in FIG. 3, the swing motion imparting mechanism described above has a roller 32 mounted on the end of the arm 31 on the opposite side of the mirror 20 (or the concave mirror 21), and the roller 32 is highly displaced. Mirror 20 (or concave mirror 21) when positioned in the
Is composed of a plate cam 35 that applies a displacement motion to the roller 32 so as to block the incident optical path A, and a motor 39 that rotationally drives the plate cam 35.

As shown in FIG. 4, instead of the swinging motion imparting mechanism composed of a roller provided at one end of the arm and a plate cam imparting a predetermined displacement motion to the roller, as shown in FIG.
The magnetic body 42 attached to the end of the arm 41 on the side opposite to the mirror 20 (or the concave mirror 21) and the magnetic body 42 are arranged to face each other with the magnetic body 42 sandwiched between columns 47, and the magnetic body 42 is attracted by alternately energizing. A pair of electromagnets 45 and 46 for imparting a swinging motion to the arm 41 are provided, and when one electromagnet 45 is in operation, the mirror
20 (or concave mirror 21) is configured to block incident light.

In place of the above-mentioned driving means, an arm having a mirror mounted on its tip and an oscillating movement imparting mechanism driving means for blocking the incident optical path by the mirror at one reversal point of the oscillating movement of the arm are replaced. , A block-shaped slider in which a mirror is fitted in a hole provided at a predetermined position and which linearly reciprocates in a plane perpendicular to the incident optical path A on a housing with a rail, and at one inversion point of the reciprocating motion of the slider. The mirror blocks the incident light path,
A reciprocating motion imparting mechanism for driving the slider so as to stop for a predetermined time, and a drive means composed of the mechanism are provided.

As illustrated in FIG. 5, the reciprocating motion imparting mechanism described above includes a plunger 51 attached to the slider 50, and a solenoid coil for attracting the plunger 51 when energized.
52 and a spring that biases and moves the slider 50 in the direction opposite to the solenoid coil 52.

Alternatively, instead of the swing motion imparting mechanism illustrated in FIG. 5, as illustrated in FIG. 6, a rack (not shown) mounted on a lower portion or an upper portion of the slider 60, and a pinion 65 that meshes with the rack, A reciprocating motion imparting mechanism including a pinion 65 and a motor 64 for imparting normal and reverse rotational motions.

As illustrated in FIG. 7, in place of either of the above-mentioned two driving means, a mirror 20 (or concave mirror 21) and windows 72 are alternately arranged on the same circle at equal pitches. When the plate 70 and the mirror 20 (or the concave mirror 21) block the incident optical path A, the rotating plate 70 is stopped for a predetermined time.
The driving means is composed of a motor 74 that rotationally drives 70.

[0025]

According to the present invention, on the front surface of an infrared detector in which a plurality of infrared detecting elements cooled to a predetermined low temperature are arranged in parallel, the incident light to the infrared detecting element is blocked and the reflecting surface faces the infrared detecting element. It is configured to insert a mirror in front of the infrared detector.

Therefore, when the mirror is inserted into the incident optical path immediately before or during the detection of the infrared ray radiated by the object by the infrared ray detector, the infrared ray is blocked from entering the infrared ray detecting element and the mirror is detected by the infrared ray detecting element. The radiant energy emitted at a very low temperature is reflected toward the infrared detecting element. Therefore, almost no external energy is incident on the infrared detection element.

In this state, the processing circuit corrects the output (photocurrent) of each infrared detecting element to be uniform. In this way, the photocurrent of each infrared detection element is uniformly corrected in the state where almost no external energy is incident, so the dispersion of the responsivity of each infrared detection element and the dispersion of the dark current are corrected. it can.

When the mirror is a concave mirror, almost all of the cryogenic radiant energy emitted by the infrared detecting element returns to the infrared detecting element and the infrared detecting element is maintained in the cryogenic state. Therefore, the variation in responsivity,
Also, the accuracy of correction of variations in dark current is further improved.

In any of the driving means according to any one of claims 2 to 9, the operating mode of the infrared imager (whether the infrared imager is mounted on a moving object or used, or installed on the ground) is used. It is possible to correct variations in responsivity and variations in dark current in a short time regardless of the operating mode) and the operating environment (ambient temperature, weather such as fine rain).

[0030]

The present invention will be described in detail with reference to the drawings. The same reference numerals indicate the same objects throughout the drawings.

FIG. 1 is a diagram showing the principle of the present invention, which is shown in FIG.
(B) is a diagram for explaining the operation of the present invention, and FIG.
4 is a perspective view of the second embodiment. FIG. 5 is a sectional view of the third embodiment, FIG. 6 is a perspective view of the fourth embodiment, and FIG. 7 is a perspective view of the fifth embodiment.

As shown in detail in FIG. 2, the infrared detecting elements 3 of the infrared detector 1 are arranged on the surface of the substrate 2 made of sapphire or the like at an equal pitch in the longitudinal direction. The substrate 2 is mounted on a base 4 in which a cooler 5 such as liquid nitrogen and a Joule Thomson cooler is installed, and the infrared detection element 3 is cooled to an extremely low temperature (around 80K), and the energy KT (K: The influence of Boltzmann's constant and T is absolute temperature is excluded.

Further, a cold aperture 6 is mounted on the base 4 so as to surround the arrayed infrared detecting elements 3 to improve the spatial resolution of the infrared detector 1.
As shown in FIG. 1, the infrared imaging device of the present invention converges the infrared rays radiated by an object into parallel rays by the objective lens system 7 and converges the rays on the light receiving surface of the infrared detection element 3 of the infrared detector 1 to form the infrared rays. Is detected, and the photocurrent output from the infrared detection element 3 is amplified by the amplifier circuit 11 and is displayed on the CRT monitor 13 via the video circuit 12.

Reference numeral 20 is a mirror which is inserted between the infrared detector 1 and the objective lens system 7 so that the reflection surface faces the infrared detection element 3 and blocks the incident optical path of the infrared detection element 3. Reference numeral 21 denotes an infrared detector 1 and an objective lens system 7 in place of the mirror 20 so that the reflection surface faces the infrared detection element 3.
It is a concave mirror that is inserted between and to block the light incident on the infrared detection element 3.

Reference numeral 100 is a driving means for inserting the mirror 20 into the incident optical path for a predetermined time (for example, 2 seconds). Reference numeral 14 denotes a processing circuit connected to the amplifier 11 so as to uniformly correct the output of each infrared detection element 3 with the mirror 20 blocking the incident light.

Numeral 15 is a driving means 100 for operating the infrared imager and immediately before or during the detection of infrared rays radiated by an object.
Is a control unit for instructing the processing circuit 14 to execute a predetermined correction process when the mirror 20 is inserted in the incident optical path.

Immediately before or during the detection of the infrared rays radiated by the object by the infrared detector 1, when the mirror 20 is inserted in the incident optical path (shown by the dotted line A), the infrared rays radiated by the object are shown in FIG.
As shown in (A), it does not enter the infrared detector 1. On the other hand, since the mirror 20 reflects the radiant energy of the cryogenic temperature emitted by the infrared detector 1 toward the infrared detection element 3, the external energy incident on the infrared detection element 3 is almost eliminated.

In this state, each infrared detecting element 3
A correction value is calculated by the processing circuit 14 for each infrared detection element 3 so that the output (photocurrent) becomes uniform. Since the photocurrents of the respective infrared detection elements 3 are uniformly corrected in the state where almost no external energy is incident, it is possible to correct the variation of the responsivity of the respective infrared detection elements 3 and the variation of the dark current. .

When the infrared imaging device operates and each infrared detecting element 3 receives the infrared rays radiated by the object and outputs a photocurrent, the processing circuit 14 calculates for each infrared detecting element 3 on the photocurrent. The above-mentioned correction value is superimposed and sent to the amplifier circuit 11 and amplified by the amplifier circuit 11.

Therefore, the reliability of the image quality obtained by the infrared imager is high. Further, as shown in FIG. 2B, when the concave mirror 21 is inserted into the incident optical path, almost all of the cryogenic radiant energy emitted by the infrared detecting element 3 returns to the infrared detecting element 3 and the infrared detecting element 3 Is maintained at a very low temperature, so variations in responsivity,
Also, the accuracy of correction of variations in dark current is further improved.

An embodiment of the driving means 100 having a swinging motion imparting mechanism will be described below with reference to FIGS. FIG.
In the reference numeral 31, the support shaft 33 provided on the stand 34 is used as an axis,
The arm swings in a plane perpendicular to the incident light path A. The mirror 20 (or the concave mirror 21) is fitted into a hole provided at one end of the arm 31. A roller 32 is rotatably attached to the other end of the arm 31.

35 is rotated by driving a motor 39,
This is a plate cam that imparts radial displacement motion to the roller 32 that is in contact with the outer peripheral surface. Shaft 33 of arm 31 and roller
One end of the tension coil spring 36 is fixed between 32, and the other end of the tension coil spring 36 is fixed to a fixed object.
The roller 32 is pressed against the outer peripheral surface of the plate cam 35 by the tensile force of 36.

When the plate cam 35 rotates and the roller 32 approaches the rising of the high displacement portion of the plate cam 35, the arm 31
Starts to oscillate, and during the predetermined time (about 2 seconds) when the roller 32 is located at the high displacement portion, the shape of the cam and the arm are set so that the reflecting surface of the mirror faces the infrared detection element 3. The size of 31 and the rotation speed of the motor 39 are set.

When the mirror 20 (or the concave mirror 21) blocks the incident optical path A, the mirror reflects the cryogenic radiant energy emitted by the infrared detector toward the infrared detecting element.
When the plate cam 35 rotates and the roller 32 moves to the low displacement portion of the plate cam 35, the arm 31 swings and the mirror 20 (or the concave mirror 21) moves to a position deviated from the incident optical path A. . Therefore, the infrared rays emitted by the object are focused on the infrared detection element.

It should be noted that the motor 39 is stopped by a command from the control unit 15 when it makes one revolution. In FIG. 4, reference numeral 41 denotes an arm that swings in a plane perpendicular to the incident optical path A about a support shaft 43 provided on a stand 44 as an axis. The mirror 20 (or the concave mirror 21) is fitted in a hole provided at one end of the arm 41.

A rod-shaped magnetic body 42 is attached to the end of the arm 41 on the side opposite to the mirror 20 (or the concave mirror 21). Further, when a pair of electromagnets 45 and 46 are attached to the support column 47 so as to face each other with the magnetic body 42 sandwiched between them, and the electromagnets 45 and 46 are alternately energized, the energized electromagnet attracts the magnetic body 42 and arms.
41 swings.

The mirror 20 (or the concave mirror 21) blocks the incident optical path A when one of the electromagnets 45 is completely operated. An embodiment of the driving means 100 having a reciprocating motion imparting mechanism will be described below with reference to FIGS.

In FIG. 5, reference numeral 50 is a block-shaped slider which is guided by guide rails 57 provided on the lower plate and the upper plate of the housing 55 with rails and which reciprocates in a plane perpendicular to the incident light path A.

The slider 50 is provided with a window 25 through which incident light passes, and a hole is provided in the vicinity of and parallel to the window 25, and a mirror is provided in this hole.
20 (or concave mirror 21) is fitted. Reference numeral 51 is a rod-shaped plunger made of a magnetic material attached to one end surface of the slider 50 (end surface near the window 25). Reference numeral 52 is a solenoid coil attached to the shaft center hole of the frame 54 made of a magnetic material to attract the plunger 51.

A sleeve 53 made of a non-magnetic material is fitted in the hollow portion of the solenoid coil 52, and the attracted plunger 51 is inserted into the axial center hole of the sleeve 53. I try not to damage it.

The solenoid coil 52 is connected to a DC power supply 59. When the switch 58 is turned on by a command from the control unit 15, the solenoid coil 52 attracts the plunger 51 into the hollow portion. When the plunger 51 is attracted, the slider 50 moves in the direction of the solenoid coil 52, the mirror 20 (or the concave mirror 21) blocks the incident optical path A, and the cryogenic radiant energy emitted by the infrared detector is reflected by the mirror. It reflects in the direction of the infrared detection element.

When the solenoid coil 52 is de-energized after a predetermined time, the tension coil spring 56 attached to the mirror-side end surface of the slider 50 causes the slider 50 to move to the solenoid coil.
The window 25 is moved to the side opposite to 52, and the window 25 is moved to a position corresponding to the incident optical path A.

In FIG. 6, reference numeral 60 denotes a block-shaped slider in which a mirror 20 (or concave mirror 21) is fitted in a hole passing through the center. 61 is the upper guide rail that is parallel to the horizontal
61A, lower guide rail 61B and upper / lower guide rails
A pair of stands 61C that connect the corresponding left and right ends of 61A and 61B, respectively, are configured to be able to reciprocate the slider 60 in a plane perpendicular to the incident light path A, and have a frame-shaped front view. It is an enclosure.

A rack (not shown) is attached to the bottom of the slider 60. On the other hand, the motor 64 having the pinion 65 fixed to the motor shaft is attached to the base 63, and the pinion 65 is meshed with the rack.

When the motor 64 is rotated forward (in the direction of the dotted arrow), the slider 60 moves to a position where the mirror 20 (or the concave mirror 21) blocks the incident optical path A, and the cryogenic radiant energy emitted by the infrared detector is transferred. Mirror 20 (or concave mirror
21) is reflected in the direction of the infrared detection element.

The motor 64 is rotated in the reverse direction (in the direction of the solid arrow).
Then, the slider 60 is deviated from the incident optical path A, and the infrared rays radiated by the object are focused on the infrared detecting element.
The motor 64 may be any type of motor as long as it is a forward / reverse free motor, but the step motor is easy to rotate forward / backward, and the slider 60 is moved so that the mirror 20 blocks the incident optical path A for a predetermined time. It is preferable because it can be caused.

FIG. 7 shows an embodiment of another driving means. Figure 7
, 70 is a mirror 20 (or a concave mirror) on the same circle.
21) and a window 72 through which incident light passes are alternately arranged at equal pitches (two mirrors and two windows are arranged in the figure).

A step motor 74, for example, is mounted on the stand 75, and the motor shaft of the step motor 74 is inserted into and fixed to the center hole of the rotary plate 70. A drive means is formed by a motor 74 that rotationally drives the rotary plate 70 so that the rotary plate 70 is stopped for a predetermined time when the incident optical path A is blocked by the mirror 20 (or the concave mirror 21).

Then, the rotating plate 70 is rotated so that the mirror 20 (or the concave mirror 21) is in a position to block the incident optical path A, and the stepping motor is maintained so as to maintain the state for a predetermined time.
Stop 74.

As a result, the cryogenic radiation energy emitted by the infrared detector is transferred to the mirror 20 (or the concave mirror 2).
1) is reflected in the direction of the infrared detection element. Window 7 after a predetermined time
The step motor 74 is rotated by a predetermined angle so that 2 is located in the incident optical path A, so that the infrared rays emitted by the object pass through the window 72 and are condensed on the infrared detecting element.

[0061]

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

If the mirror is inserted into the incident optical path immediately before or during the detection of the infrared rays emitted by the object by the infrared detector, the infrared rays are blocked from entering the infrared detecting element and the mirror emits the infrared detecting element. The radiant energy at extremely low temperature is reflected toward the infrared detecting element. Therefore, the photocurrent of each infrared detecting element can be uniformly corrected in a state where there is almost no external energy incident on the infrared detecting element.

Therefore, it is possible to correct the variation in the responsivity of each infrared detecting element and the variation in the dark current, and the reliability of the image quality is high. Further, when the mirror is a concave mirror, the accuracy of correction of variations in responsivity and variations in dark current is further improved.

In any of the driving means according to any one of claims 2 to 9, the operating mode of the infrared imaging device (whether the infrared imaging device is mounted on a moving object or used, or installed on the ground) is used. It is possible to correct variations in responsivity and variations in dark current in a short time regardless of the operating mode) and the operating environment (ambient temperature, weather such as fine rain).

[Brief description of drawings]

FIG. 1 is a diagram showing the principle of the present invention.

2 (A) and 2 (B) are diagrams for explaining the operation of the present invention. FIG.

FIG. 3 is a diagram of a first embodiment.

FIG. 4 is a perspective view of a second embodiment.

FIG. 5 is a sectional view of a third embodiment.

FIG. 6 is a perspective view of a fourth embodiment.

FIG. 7 is a perspective view of a fifth embodiment.

FIG. 8 is a block diagram of an infrared imaging device.

[Explanation of symbols]

 1 infrared detector 2 substrate 3 infrared detector 5 cooler 6 cold aperture 7 objective lens system 11 amplifier 12 video circuit 13 CRT monitor 14 processing circuit 15 control unit 100 driving means 20 mirror 21 concave mirror 25,72 window 31 arm 32 roller 33,43 Spindle 35 Plate cam 36,56 Tension coil spring 39,64,74 Motor 42 Magnetic body 45,46 Electromagnet 50,60 Slider 51 Plunger 52 Solenoid coil 55,61 Housing with rails 64,74 Motor 70 Rotating plate

Front page continued (72) Inventor Hironori Ishizuka 1015 Kamiodanaka, Nakahara-ku, Kawasaki, Kanagawa Prefecture, Fujitsu Limited (72) Inventor Takayuki Tsuboi, 1015, Kamedotachu, Nakahara-ku, Kawasaki, Kanagawa Prefecture, Fujitsu Limited (72) Inventor Hirokazu Hara 1015 Kamiodanaka, Nakahara-ku, Kawasaki City, Kanagawa Prefecture, Fujitsu Limited

Claims (9)

[Claims] 1. An infrared detector in which infrared detecting elements cooled to a predetermined low temperature are arranged in parallel, and a reflecting surface is inserted so as to face the infrared detecting element so as to block an incident optical path on the front surface of the infrared detector. A mirror, a driving unit that inserts the mirror into the incident optical path for a predetermined time, and a processing circuit that uniformly corrects the output of each infrared detection element in a state where the mirror blocks the incident optical path.
An infrared imaging device characterized by being provided. 2. The infrared imaging device according to claim 1, wherein the mirror is a concave mirror. 3. An arm having a mirror mounted on a tip thereof, the driving means swinging in a plane perpendicular to an incident light path about a spindle provided on a stand, and a swinging motion of the arm. 3. The infrared ray according to claim 1 or 2, further comprising: a swing motion imparting mechanism that drives the arm so that the mirror blocks the incident optical path at one inversion point and stops the optical path for a predetermined time. Video equipment. 4. The swing motion imparting mechanism according to claim 3, wherein the roller mounted on the end of the arm on the side opposite to the mirror, and the mirror blocking the incident light path when the roller is located at the high displacement portion. As described above, an infrared imaging device comprising: a plate cam that imparts a displacement motion to the roller; and a motor that rotationally drives the plate cam. 5. Instead of the swing motion imparting mechanism according to claim 4, a magnetic body mounted on the end of the arm on the side opposite to the mirror and a magnetic body mounted on a support column with the magnetic body sandwiched therebetween are arranged alternately. When a current is applied to the magnet, the magnetic substance is attracted to impart a swinging motion to the arm, and a swinging motion imparting mechanism is formed by a pair of electromagnets in which the mirror blocks the incident optical path when one electromagnet is operating. The infrared imaging device according to claim 3, further comprising: 6. A block shape which is linearly reciprocating in a plane perpendicular to an incident light path on a housing with a rail, in which a mirror is fitted in a hole provided at a predetermined position, instead of the driving means according to claim 3. And a reciprocating motion applying mechanism for driving the slider so that the mirror blocks the incident optical path at one reversal point of the reciprocating motion of the slider and stops for a predetermined time. The infrared imaging device according to claim 1 or 2. 7. The reciprocating motion imparting mechanism according to claim 6, wherein a plunger attached to the slider, a solenoid coil for attracting the plunger by energizing the slider, and a biasing movement of the slider in a direction opposite to the solenoid coil. An infrared imaging device characterized by comprising a spring. 8. A reciprocating motion imparting mechanism according to claim 7, a rack mounted on a lower part or an upper part of a slider, a pinion meshing with the rack, and a motor for imparting normal and reverse rotational motion to the pinion. 7. The infrared imaging device according to claim 6, further comprising a reciprocating motion imparting mechanism including. 9. A rotating plate in which mirrors and windows are alternately arranged at equal pitches on the same circle instead of the driving means according to claim 3 or 6, and when the mirror blocks an incident light path. 3. The infrared imaging device according to claim 1, further comprising a driving unit that includes a motor that rotationally drives the rotary plate so as to stop the rotary plate for a predetermined time.