JP3175485B2 - Infrared detector - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an infrared detector for detecting infrared radiation emitted from a human body or the like.

[0002]

2. Description of the Related Art As an infrared detector for detecting infrared rays emitted from a human body or the like, for example, Japanese Patent Application Laid-Open No. 56-12843.
There is an infrared detector disclosed in Japanese Patent Laid-Open No. 2 (Kokai) No. 2 and a main configuration of the infrared detector disclosed is shown in FIG. As shown in the figure, the infrared detector 11 includes an infrared detecting element 16 for detecting infrared light, and a chopper mechanism 23 for repeatedly introducing and blocking infrared light to the infrared detecting element 16, and the chopper mechanism 23 Is configured to include a propeller-shaped (rotating wing-shaped) infrared shielding plate 12 for blocking infrared radiation and a motor 72, and the motor 72
By rotating, the introduction and cutoff of infrared light to the infrared detection element 16 are repeatedly performed. Incidentally, the infrared detection element 16 is formed of elements such as a pyroelectric element, a thermoresistance element, and a thermoelectric element, and an infrared analysis device (not shown) is connected to the infrared detection element 16,
The infrared analyzer analyzes the intensity of the infrared light introduced into the infrared detecting element 16.

FIG. 10 shows another example of an infrared detector.
FIG. 1 shows a main configuration of an infrared detector disclosed in Japanese Patent Application Laid-Open No. 58-129334. The chopper mechanism 23 of the infrared detector 11 includes two infrared shielding plates 12.
a, 12b, and a piezoelectric bimorph vibrator 83, and the piezoelectric bimorph vibrator 83 causes the infrared shielding plate 12b to vibrate by a predetermined amount of displacement to form an infrared transmitting slit 80 formed on the infrared shielding plate 12b and an infrared shielding slit. By adjusting or shifting the position of the infrared transmitting slit 80 formed on the plate 12a, the introduction and blocking of the infrared light to the infrared detecting element 16 are repeatedly performed.

[0004]

However, the infrared detector 11 as shown in FIG. 9 rotates the rotary wing-shaped infrared shielding plate 12 to introduce and block infrared radiation to the infrared detecting element 16. For this reason, the infrared shielding plate 12 is bulky, and the motor 72 for rotating the infrared shielding plate 12 is also bulky, so that there is a problem that the infrared detector 11 becomes large. Also, an infrared detector as shown in FIG.
In (11), it is necessary to apply a high voltage of several tens to several hundreds of volts to the piezoelectric bimorph vibrator 83 in order to displace the infrared shielding plate 12b by a predetermined displacement amount, and a large transformer or the like is required for that purpose. Therefore, there is a problem that the infrared detector 11 increases in size and the cost increases similarly to the above, and further, in this device, by applying a high voltage to the piezoelectric bimorph vibrator 83, There is also a problem that noise of the infrared detection signal detected by the detection element 16 is induced.

[0005] The present invention has been made to solve the above-mentioned conventional problems, and an object of the present invention is to provide a small-sized infrared detector having less noise in an infrared detection signal.

[0006]

In order to achieve the above object, the present invention is configured as follows. That is, the present invention is an infrared detecting element, an infrared detector provided with a chopper mechanism for repeatedly introducing and blocking infrared light to the infrared detecting element, the chopper mechanism is an infrared ray blocking body that blocks infrared light A guide portion for guiding the sliding movement of the infrared shield; the infrared shield is slidably provided on the guide portion; at least one permanent magnet is connected to the infrared shield; At one end in the sliding direction, a fixed magnet having the same polarity as that of the permanent magnet is opposed to the permanent magnet via a gap, and at the other end of the permanent magnet in the sliding direction, an electromagnet is opposed to the other end via the gap. And changing the magnitude of the repulsive force between the electromagnet and the permanent magnet by changing the amount of current applied to the electromagnet that generates a magnetic field of the same polarity as the opposing permanent magnet to change the magnitude of the repulsive force between the electromagnet and the permanent magnet. Chopper drive unit for sliding is configured as being provided.

In addition, the chopper drive section slides the infrared ray interrupter by applying a continuous polarity reversal current to the electromagnet to generate a magnetic field of the same polarity and a reversal polarity of the opposite permanent magnet in the electromagnet alternately. The polarity reversing drive means for moving is also a characteristic configuration of the present invention.

Further, the infrared detecting element is a pyroelectric element, the infrared detecting element is a thermal resistance element, the infrared detecting element is a thermoelectric element, and the infrared detecting element is an array of a plurality of infrared detecting sections. The infrared ray array element formed as described above is also a characteristic configuration of the present invention.

[0009]

In the present invention having the above-described structure, a fixed magnet having the same polarity as the permanent magnet is disposed at one end of the permanent magnet in the sliding direction so as to be opposed to the permanent magnet with a gap therebetween. Generates a repulsive magnetic force. On the other hand, an electromagnet is disposed at the other end of the permanent magnet in the sliding direction with a gap therebetween, and when the amount of current or the polarity applied to the electromagnet is changed by the chopper drive unit, The magnetic action (repulsive or attractive magnetic force) between the opposing permanent magnet and the electromagnet changes, and, for example, by changing the amount of current applied to the electromagnet that generates a magnetic field of the same polarity as the opposing permanent magnet, The magnitude of the repulsive magnetic force with the magnet is varied. Then, the balance between the magnitude of the repulsive magnetic force between the permanent magnet and the electromagnet and the magnitude of the repulsive magnetic force between the permanent magnet and the fixed magnet changes, and the infrared blocking body slides while being guided by the guide portion.

[0010]

Embodiments of the present invention will be described below with reference to the drawings. In the description of the present embodiment, the same symbols are assigned to the same parts as in the conventional example, and the detailed description thereof is omitted.
FIG. 1 shows a main configuration of an infrared detector according to a first embodiment of the present invention. In the figure, the infrared detector 11 includes an infrared detecting element 16 and a chopper moving mechanism 23, and the chopper mechanism 23 is an infrared shielding plate that blocks infrared rays.
It has 12 parts. The infrared shielding plate 12 is formed of a thin rectangular plate made of aluminum, resin, or the like.
On both sides of the infrared shielding plate 12, guide portions 17 for guiding the sliding movement of the infrared shielding plate 12 are fixed to the base 8. Guide part 17
Is formed with a guide groove 9, and the arm 6 of the infrared shielding plate 12 is slidably fitted in the guide groove 9, whereby the infrared shielding plate 12 is slidable up and down in the figure. Has become.

A permanent magnet 13 is connected to one side (right side in the figure) of the infrared shielding plate 12 via an arm 6, and a top surface 3 of the permanent magnet 13 is an S pole, The bottom side 4 of the magnet 13 is an N pole. On the top side 3 of the permanent magnet 13, a fixed magnet 14 made of a permanent magnet is opposed to the permanent magnet 13 via a gap, and the bottom side of the fixed magnet 14 has the same polarity as the top side 3 of the permanent magnet 13, that is, S It is a pole. An electromagnet 15 fixed to the base 8 with a gap therebetween is disposed on the bottom side 4 of the permanent magnet 13. In other words, a permanent magnet
A fixed magnet 14 having the same polarity as the top surface 3 of the permanent magnet 13 is disposed at one end of the slide direction 13 (up-down direction in the drawing), and an electromagnet 15 is disposed at the other end in the slide direction. ing.

The electromagnet 15 is formed by winding a winding 19 around a cylindrical bobbin 18 having a flange formed of resin, and a chopper drive unit 22 is connected to the electromagnet 15. The chopper drive unit 22 applies a current to the electromagnet 15 to generate a magnetic field having the same polarity as that of the permanent magnet 13 facing the electromagnet 15, that is, a magnetic field such that the upper (top) side of the electromagnet 15 becomes an N pole. By changing the amount of current applied to the electromagnet 15 to change the magnitude of the repulsive magnetic force between the electromagnet 15 and the permanent magnet 13,
Thus, the infrared shielding plate 12 is slid and moved, for example, by applying a voltage of 0.3 V to the winding 19 of the electromagnet 15 and varying the amount of applied current within a range of 0 to 30 mA.

FIG. 2 is a block diagram showing a main configuration of the infrared detector 11 of this embodiment. As shown in FIG. 2, the infrared detector 16 is connected to the infrared detector 16 via a signal amplifier 24. An infrared analyzer is connected and the infrared detector 16
The infrared detection signal detected in is amplified by the signal amplifier 24,
It is to be analyzed by an infrared analyzer. Further, as shown in FIG. 3A, the infrared detecting element 16 of the present embodiment is formed by a pyroelectric element of an infrared array element in which a plurality of infrared detecting sections 5 are arranged in a two-dimensional array without any gap. Have been.

This embodiment is configured as described above.
Next, the operation will be described with reference to FIG. As shown in FIG. 4A, the top side 3 of the permanent magnet 13 is an S pole, and the bottom side of the fixed magnet 14 facing the top side 3 of the permanent magnet 13 is also an S pole. Therefore, a repulsive magnetic force is generated between the permanent magnet 13 and the fixed magnet 14. on the other hand,
A current is applied to the electromagnet 15 from the chopper driving unit 22 to the winding 19 of the electromagnet 15, and the top side of the electromagnet 15 is an N pole, and the bottom side 4 of the permanent magnet 13 facing the electromagnet 15 is also an N pole. Therefore, a repulsive magnetic force is also generated between the permanent magnet 13 and the electromagnet 15. Then, for example, when a current of 30 mA is applied to the electromagnet 15 from the chopper drive unit 22,
When the repulsive magnetic force generated between the electromagnet 15 and the permanent magnet 13 and the repulsive magnetic force of the fixed magnet 14 and the permanent magnet 13 are in a balanced state, the infrared shielding plate 12 is in a position as shown in FIG. Then, at this time, the infrared light that is going to enter the infrared detection element 16 is blocked by the infrared blocking plate 12.

When the amount of current applied from the chopper drive unit 22 to the electromagnet 15 is reduced to less than 30 mA, the intensity of the magnetic field generated in the electromagnet 15 is reduced, and therefore the repulsive force between the electromagnet 15 and the permanent magnet 13 is reduced. The repulsive force between the permanent magnet 13 and the electromagnet 15 is smaller than the repulsive force between the permanent magnet 13 and the fixed magnet 14, and the balance between the two repulsive forces changes.
As shown by the arrow in the figure, the permanent magnet 13 approaches the electromagnet 15 side, whereby the infrared shielding plate 12 connected to the permanent magnet 13 is also guided by the guide portion 17, and is shown in FIG. As shown in the figure. Then, as described above, when the infrared shielding plate 12 moves downward, the introduction of infrared light to the infrared detecting element 16 is not interrupted by the infrared shielding plate 12, so that infrared light is introduced to the infrared detecting element 16. Done.

When the amount of current applied from the chopper drive unit 22 to the electromagnet 15 is increased again, the intensity of the magnetic field generated in the electromagnet 15 is increased again, and the repulsive magnetic force between the electromagnet 15 and the permanent magnet 13 is also increased. Conversely, the permanent magnet 13 moves to the upper side in the figure, and the infrared shielding plate 12 also slides to the upper side in the figure. In this way, by varying the amount of current applied from the chopper drive unit 22 to the electromagnet 15, the infrared shielding plate 12 slides up and down together with the permanent magnet 13, thereby introducing infrared light to the infrared detecting element 16. And interruption are repeatedly performed. Then, the infrared detecting element 16
Is amplified by the signal amplifier 24 and added to the infrared analyzer, and the infrared analyzer analyzes the infrared intensity.

According to this embodiment, the above operation causes the current for generating a magnetic field of the same polarity as that of the permanent magnet 13 to be generated by the chopper driving unit.
The voltage applied to the electromagnet 15 is changed by 22, the amount of current applied to the electromagnet is changed, the magnitude of the repulsive force between the electromagnet 15 and the permanent magnet 13 is changed, and the infrared shielding plate 12 is slid, thereby detecting infrared light. Since the introduction and cutoff of infrared rays to the element 16 are repeatedly performed, the operation of the chopper mechanism 23 can be performed by an easy operation of changing the amount of current applied from the chopper drive unit 22 to the electromagnet 15. And
The amount of current applied from the chopper drive unit 22 to the electromagnet 15 is 0 to 30.
Since only a small amount of current such as mA is required and the applied voltage may be as small as 0.3 V, it is possible to reduce the size of the power supply and the like, and it is necessary to provide a motor and a large transformer as in the conventional infrared detector 11. In addition, since the infrared shielding plate 12 does not need to be large, the infrared detector can be a small device with little noise.

FIG. 5 shows a main configuration of a second embodiment of the infrared detector according to the present invention. In this embodiment, the first
The configuration is almost the same as that of the first embodiment.
What is different from this embodiment is that one of the arms 6 is bent toward the rear side in the figure and the permanent magnet 13 is connected to the rear side of the infrared shielding plate 12.

In this embodiment, the operation is the same as that of the first embodiment, and the same effects can be obtained. Further, in the present embodiment, since the permanent magnet 13, the fixed magnet 14, and the electromagnet 15 are disposed on the rear side of the infrared shielding plate 12, it is desired to reduce the width of the infrared detector 11 (the length in the X direction in the drawing). It is advantageous in some cases.

FIG. 6 shows a main part of a third embodiment of the infrared detector according to the present invention. This embodiment is different from the first and second embodiments in that a permanent magnet support 26 is provided on the bottom surface side of the infrared shielding plate 12, and the permanent magnet 13 is provided via the permanent magnet support 26. That is, it is connected to the infrared shielding plate 12.

This embodiment operates in the same manner as the first and second embodiments, and can achieve the same effects.

FIG. 7 shows a main part of a fourth embodiment of the infrared detector according to the present invention. In this embodiment, the first
What is different from the third embodiment is that the infrared shielding plate
Permanent magnets 13a and 13b are located above and below 12 respectively.
Is concatenated. The permanent magnet 13a is supported by a frame-shaped support 10 formed above the infrared shielding plate 12, and the top surface 3 of the permanent magnet 13a is an S pole. The magnet 13b is directly connected to the bottom side of the infrared shielding plate 12, and the bottom side 4 of the permanent magnet 13b is an N pole. The bottom surface of the fixed magnet 14 has an S pole and the same polarity as the top surface 3 of the permanent magnet 13a, while the top surface of the electromagnet 15 has an N pole. An electric current is applied from 22 and the top side of the electromagnet 15 and the bottom side 4 of the permanent magnet 13b have the same polarity.

In the case where a plurality of permanent magnets are connected to the infrared shielding plate 12 as in this embodiment, the permanent magnets
13, one end of the sliding direction (vertical direction in the drawing), that is, in this embodiment, a permanent magnet 13
By disposing the fixed magnet 14 having the same polarity as the top surface 3 of the permanent magnet 13a, a repulsive magnetic force is generated between the permanent magnet 13a and the fixed magnet 14, and the other side of the permanent magnet 13 in the sliding direction is provided. If the electromagnet 15 is arranged at the end, that is, in the present embodiment, on the bottom side 4 of the permanent magnet 13b, and the electromagnet 15 generates a magnetic field having the same polarity as the permanent magnet 13b,
A repulsive magnetic force is generated between the permanent magnet 13b and the electromagnet 15.

This embodiment is configured as described above.
As in the first to third embodiments, the amount of current applied from the chopper drive unit 22 to the electromagnet 15 is varied, so that the repulsive magnetic force between the electromagnet 15 and the permanent magnet 13b, the permanent magnet 13a and the fixed magnet 14 The same operation as in the above embodiment is performed by varying the balance with the repulsive magnetic force between them, and the same effect can be obtained.

FIG. 8 shows a main configuration of a fifth embodiment of the infrared detector according to the present invention. This embodiment is the fourth embodiment.
What is different from the embodiment of the present invention is that the permanent magnets 13a, 13b
Are connected to the arms 6 on both ends of the infrared shielding plate 12. This embodiment also operates in the same manner as the above embodiment, and can achieve the same effects.

The present invention is not limited to the above-described embodiment, but can adopt various embodiments. For example, in the above embodiment, the top surface 3 of the permanent magnet 13 is an S pole and the bottom surface 4 is an N pole.
The pole may be used, and the bottom side of the permanent magnet 13 may be used as the S pole.
In such a case, the bottom surface of the fixed magnet 14 is set to the N pole, and the top surface of the electromagnet 15 is set to the S pole.
May be varied.

In the above embodiment, for example, a current of 0 to 30 mA is applied to the winding 19 of the electromagnet 15 from the chopper driving unit 22 to apply a voltage of 0.3 V. The values of the current and the voltage applied to the winding 19 are not particularly limited and are appropriately set.For example, if the number of windings of the winding 19 around the bobbin 18 is increased, a lower voltage is applied. In this case, the same magnetic force as in the above embodiment can be obtained.

Further, in the above embodiment, the chopper driving section
22, a series current is applied to the winding 19 of the electromagnet 15 so that the magnetic pole on the top side of the electromagnet has the same polarity as the magnetic pole on the bottom side 4 of the fixed magnet 13, but the chopper drive unit 22 is continuous. The applied polarity inversion current is applied to the winding 19 of the electromagnet 15 to alternately generate a magnetic field having the same polarity as the permanent magnet 13 and a magnetic field having the inverted polarity.
, The repulsive magnetic force and the attractive magnetic force of the electromagnet 15 and the permanent magnet 13 are generated alternately, and thereby, the polarity inversion driving means for slidingly moving the infrared shielding plate 12 in the vertical direction may be used. As described above, when the chopper drive unit 22 is a polarity inversion drive unit, the current for generating the magnetic field of the inversion polarity with the permanent magnet 13 is, for example, −
Even if only a small polarity reversal current and a polarity reversal voltage are applied, such as 1 mA and a voltage of -0.1 V, a sufficient attractive magnetic force is generated between the permanent magnet 13 and the electromagnet 15. What is necessary is just to add a polarity inversion current and a polarity inversion voltage.

Further, in the above embodiment, the fixed magnet 14 is
Although the permanent magnet is used, the fixed magnet 14 may be an electromagnet in which the direction and strength of the generated magnetic field are fixed.

Further, in the above embodiment, the permanent magnet 13 is
Although two or more permanent magnets 13 are provided, three or more permanent magnets 13 may be provided, and one or more fixed magnets 14 and electromagnets 15 are not necessarily provided as in the above embodiment. I do not care.

Further, in the above-described embodiment, the rectangular infrared shielding plate 12 is provided as an infrared shielding body for shielding infrared rays. However, the infrared shielding body is not always a rectangular infrared shielding plate. Or an infrared shield other than the infrared shield plate. However, if the infrared shield is made large, the infrared detector becomes bulky by that much, so that the infrared shield is desirably of such a size and shape that it is as small as possible.

Further, in the above embodiment, the infrared detector 16
Are a plurality of infrared detectors 5 as shown in FIG.
Are arranged in the form of a two-dimensional array without any gaps, but the infrared detecting element 16 includes a plurality of infrared detecting sections 5 formed in a two-dimensional array through the gaps as shown in FIG. , An infrared array element in which a plurality of infrared detection units 5 are arranged in a one-dimensional array, or an infrared detection element formed by one infrared detection unit 5. Absent.

Further, in the above embodiment, the infrared detecting element
Although the infrared detecting element 16 is formed by a pyroelectric element, the infrared detecting element 16 is not limited to the pyroelectric element, and may be another detecting element such as a thermoresistive element or a thermoelectric element.

Further, in the above embodiment, the infrared detecting element
4, as shown in FIG. 4, provided on the upper side of the guide portion 17, infrared rays are introduced into the infrared detecting element 16 when the infrared shielding plate 12 is moved downward, and the infrared shielding plate 12 is 4A, the introduction of infrared light to the infrared detecting element 16 is blocked.
As shown in FIG. 30, the infrared detecting element 16 is provided below the guide portion 17, and conversely, when the infrared shielding plate 12 is on the upper side, infrared light is introduced into the infrared detecting element, and The infrared rays may be blocked when the blocking plate 12 is on the lower side.

Further, a permanent magnet 13, a fixed magnet 14, an electromagnet
There is no particular limitation on the location of the 15
A fixed magnet having the same polarity as the permanent magnet may be disposed at one end of the sliding direction of the permanent magnet 13 with a space therebetween, and the electromagnet 15 may be disposed at the other end of the sliding direction of the permanent magnet 13 with a space therebetween.

[0036]

According to the present invention, an infrared shielding body for shielding infrared rays from the infrared detecting element is slidably provided, and a permanent magnet connected to the infrared shielding plate is permanently attached to one end in the sliding direction of the permanent magnet. A fixed magnet having the same polarity as the magnet is opposed to the permanent magnet with a gap therebetween, thereby generating a repulsive magnetic force between the permanent magnet and the fixed magnet. On the other hand, the permanent magnet is opposed to the other end in the sliding direction with a gap therebetween. By changing the amount of applied current and the polarity of the applied electromagnet by the chopper drive unit, the magnetic force such as the magnitude of the repulsive magnetic force generated between the permanent magnet and the electromagnet is changed, and the magnetic force between the permanent magnet and the electromagnet is changed. By desirably changing the balance between the action and the repulsive magnetic force between the fixed magnet and the permanent magnet, it is possible to slide the infrared shield as desired even if the amount of current applied to the electromagnet is not large. And blocking the introduction of infrared outside line detection device can be performed easily repeated.

For this reason, as in the conventional apparatus for introducing and blocking infrared rays to the infrared detecting element by rotating a propeller-shaped infrared shield, the infrared shield is bulky and the apparatus becomes large. There is no need for a large motor or the like for rotating and moving the infrared cut-off body, and a large transformer for driving the piezoelectric bimorph vibrator like a device for moving the infrared cut-off body by a piezoelectric bimorph vibrator is required. Since there is no need to do so, the size and weight of the device can be reduced by that much, and since no noise is generated by a large transformer, the infrared detector can be a small device with little noise.

[Brief description of the drawings]

FIG. 1 is a main part configuration diagram showing a first embodiment of an infrared detector according to the present invention.

FIG. 2 is an explanatory diagram showing a main part configuration of an infrared detector of the present invention by a block diagram.

FIG. 3 is an infrared detecting element in the infrared detector of the present invention.
FIG. 9 is an explanatory diagram showing an example of an arrangement state of an infrared detector 5 forming 16.

FIG. 4 is an explanatory diagram showing an operation of the infrared detector according to the first embodiment of the present invention.

FIG. 5 is a main part configuration diagram showing a second embodiment of the infrared detector according to the present invention.

FIG. 6 is a main part showing an infrared detector according to a third embodiment of the present invention.

FIG. 7 is a main part configuration diagram showing a fourth embodiment of the infrared detector according to the present invention.

FIG. 8 is an explanatory view showing a fifth embodiment of the infrared detector according to the present invention.

FIG. 9 is an explanatory diagram of a main part showing an example of a conventional infrared detector.

FIG. 10 is an explanatory diagram of a main part showing another example of a conventional infrared detector.

[Explanation of symbols]

 3 Top side 4 Bottom side 11 Infrared detector 12 Infrared shield 13 Permanent magnet 14 Fixed magnet 15 Electromagnet 16 Infrared detector 22 Chopper drive

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int.Cl. ⁷ , DB name) G01J 1/04 G01J 5/62 G01V 8/12 H01F 7/16

Claims (6)

(57) [Claims] 1. An infrared detector comprising: an infrared detection element; and a chopper mechanism for repeatedly introducing and blocking infrared light to the infrared detection element, wherein the chopper mechanism includes an infrared cutoff for blocking infrared light, It has a guide portion for guiding the sliding movement of the infrared shield, the infrared shield is slidably provided on the guide portion, and at least one permanent magnet is connected to the infrared shield, At one end in the sliding direction, a fixed magnet having the same polarity as that of the permanent magnet is opposed to the permanent magnet via a gap, and at the other end of the permanent magnet in the sliding direction, an electromagnet is opposed to the permanent magnet via a gap. By changing the magnitude of the repulsive force between the electromagnet and the permanent magnet by varying the amount of current applied to the electromagnet that generates a magnetic field of the same polarity as the opposing permanent magnet, the infrared blocking body slides. An infrared detector provided with a chopper driving unit for moving the chopper. 2. A chopper driving unit slides an infrared ray interrupter by applying a continuous polarity reversal current to an electromagnet and alternately generating a magnetic field having the same polarity and a reversal polarity with the opposing permanent magnet in the electromagnet. 2. An infrared detector according to claim 1, wherein said means is a polarity inversion driving means. 3. The infrared detector according to claim 1, wherein the infrared detector is a pyroelectric element. 4. The infrared detector according to claim 1, wherein the infrared detection element is a thermal resistance element. 5. The infrared detector according to claim 1, wherein the infrared detection element is a thermoelectric element. 6. The infrared detector according to claim 1, wherein the infrared detector is an infrared array element in which a plurality of infrared detectors are formed in an array.