JPH10260080A - Visualizing device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To visualize a radiation image at a high degree of detection and a high degree of sensitivity with no use of a cooler, and to obtain a stable radiation image irrespective of variation in environmental temperature. SOLUTION: A converter 100 has a plurality of elements two-dimensionally arranged. Each element receivers infrared radiation 1 so as to generate a head in order to produce a displacement in accordance with the heat, and accordingly, a received rear-out light beam (j) is changed on accordance with the displacement, and is emitted to the element. An optical image of each element in accordance with the displacement is obtained, being based upon the changed and read-out light beam emitted from each element. The converter 100 is located on a closed container 102. A temperature controller 109 controls a temperature stabilizer 105 in accordance with a signal from a temperature sensor 107 for detecting a temperature of the converter 100, so as to maintain the temperature of the converter 100 at a constant value.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] 1. Field of the Invention [0002] The present invention relates to an imaging apparatus for imaging various radiation images including invisible light such as infrared rays, X-rays, and ultraviolet rays.

[0002]

2. Description of the Related Art Recently, research has been actively conducted on the use of physical information other than information obtained only from the visible light region by detecting invisible light such as infrared rays, X-rays, and ultraviolet rays.
It is expected to be applied to various industrial fields. As an example, the use of infrared light will be described.

[0003] Infrared rays are energy radiated from all objects having a temperature existing on the earth.
An object near 0K emits infrared light having a peak of 8 to 12 μm. By using this infrared ray, it is possible to detect the presence, shape, and temperature of the object even in the dark. Therefore, if this infrared light is used, for example, even at night when there is almost no light, it is possible to drive the car as if looking at the scenery of the daytime, and it is also possible to prevent illegal intruders into buildings at night without lighting. It can be easily discovered.

[0004] Because of these advantages, various approaches have been taken to detect infrared light, which is invisible light, since Herschel discovered the infrared light around 1800. Nowadays, two types of detectors have been used as infrared detectors, namely, a quantum infrared detector and a thermal infrared detector.

[0005]

However, even with today's advances in optomechatronics technology, infrared detection is not technically easy, and has not yet been widely used in the general public. The reason will be described below separately for the quantum infrared detector and the thermal infrared detector.

[0006] The quantum infrared detector is a detector that converts photon energy (E: hv) of infrared light into electron energy and detects it. The wavelength of infrared rays that is most useful in the general society is 3 to 12 μm, and the photon energy of this infrared ray is about 0.1 to 0.4 eV. This value is almost equal to the thermal energy of electrons in a normal temperature object. They are equal. Therefore, in order to convert only the incident infrared photon energy into electron energy,
The effects of the thermal energy of the electrons must be removed. That is, in the quantum infrared detector, it is essential to cool the detector and remove heat energy.

Usually, in order to suppress this thermal energy to a low level, it is necessary to cool the detector to about -200 ° C. (77 K). However, the cooler for this is large in volume and generates mechanical vibration. Life is short and expensive.
Therefore, the infrared camera using the quantum infrared detector cannot be reduced in size and cost, and is not widely used in the general society.

On the other hand, a conventional thermal infrared detector is
Converts the energy of the incident infrared rays into heat energy,
A change in the temperature of the detector is caused, and a change in the physical property value of the detector due to the change is electrically read. For example, in a resistive bolometer, the resistance value changes when the temperature changes.

This conventional thermal infrared detector does not require a large-scale cooler such as a quantum infrared detector, but has a problem in the detection principle itself. That is, in the conventional thermal infrared detector, although a temperature change of the detector due to only the incident infrared ray has to be detected, a current must be supplied to the detector in order to detect the temperature change.

That is, since the detector generates heat (usually called self-heating) due to a current for detecting a temperature change, it is difficult to detect a temperature change due to only incident infrared rays, and the detection accuracy is reduced. Was.

[0011] Further, the conversion part for converting incident infrared rays into thermal energy detects as much as possible a temperature change depending only on the thermal energy generated by the incident infrared rays.
Although supported in a state of floating from the substrate, it is necessary to build a resistance bolometer or the like in the conversion part floating from the substrate, so it is necessary to electrically connect the conversion part and the substrate with a conductive material. is there. However, since the conductive material has an extremely high thermal conductivity, the conventional thermal infrared detector cannot increase the degree of thermal insulation of the conversion part with respect to the substrate, and the detection accuracy also decreases in this regard. And the sensitivity was also reduced.

Further, the conventional thermal infrared detector has a drawback of low sensitivity. In a conventional thermal infrared detector, for example, an object having a resistance change rate of about 2% when the resistance temperature changes by 1 ° C. is used. The rate of conversion to temperature is at most about 1%. Therefore, even if the temperature of the observation object changes by 1 ° C., the resistance changes only by 0.02%.

Furthermore, in the conventional thermal infrared detector, since the obtained electric signal is extremely weak, the electric signal readout circuit is required to have a very high level of low noise, and the circuit scale is large. Was.

The situation described above is not limited to infrared rays, but also applies to other radiations.

Therefore, the present inventors have invented an imaging apparatus for imaging an image of radiation based on a completely different principle from a conventional detector, which does not require converting the energy of the radiation into electric energy.

That is, the present inventors have invented an imaging device including an optical readout radiation-displacement converter and a readout optical system. The optical readout radiation-displacement converter comprises:
It has a plurality of elements arranged two-dimensionally or two-dimensionally. Each of the elements generates heat in response to radiation, generates a displacement in accordance with the heat, and gives a change in the received readout light in accordance with the displacement and emits the readout light. The readout optical system irradiates the readout light to each of the elements, and forms an optical image corresponding to the displacement of each of the elements based on the changed readout light emitted from each of the elements.

According to this imaging device, infrared rays, X-rays,
Radiation such as ultraviolet rays is applied to each element of the optical readout type radiation-displacement converter, and in each element, the radiation is converted into heat, and displacement occurs according to the generated heat. That is, the incident radiation is converted into a displacement according to the amount. on the other hand,
The readout optical system irradiates each element of the optical readout type radiation-displacement converter with readout light of visible light or other light. Each element gives the received readout light a change in accordance with the displacement and emits the readout light, so that the radiation applied to each element is converted into a change in the readout light. Then, an optical image corresponding to the displacement of each element is formed by the readout optical system based on the changed readout light. As a result, a radiation image is formed as an optical image. This optical image can be observed with the naked eye as it is, or can be imaged by an imaging device. Since displacement detection by light can be performed with high sensitivity, the imaging device can detect radiation with high sensitivity, and thus can form an image of radiation with high sensitivity. Also, in the imaging device, unlike the above-described conventional thermal infrared detector, the radiation is not converted into a resistance value (electric signal) through heat, but the radiation is read out through heat and displacement to change in readout light. Since the conversion is performed, it is not necessary to supply a current to each element, and no self-heating occurs in each element. Therefore,
According to the imaging device, since only heat due to incident radiation is detected, an image of radiation can be formed with high detection accuracy. Needless to say, the imaging apparatus does not require a cooler which is necessary in the quantum infrared detector, as in the above-described conventional thermal infrared detector. Also,
The imaging apparatus does not read out the radiation as an electric signal, so that a reading circuit for a weak electric signal, which is required in the above-described conventional thermal infrared detector, becomes unnecessary.

As described above, according to the imaging apparatus, a radiation image can be visualized with high detection accuracy and sensitivity without the need for a cooler. If the temperature of the vessel changes, it is not possible to obtain a stable radiation image due to the influence.

The present invention has been made in view of such circumstances, and it is possible to visualize a radiation image with high detection accuracy and sensitivity without the need for a cooler, and furthermore, to cope with changes in environmental temperature. It is an object of the present invention to provide an imaging device capable of obtaining a stable image of radiation regardless of the case.

[0020]

In order to solve the above-mentioned problems, in an imaging device according to a first aspect of the present invention, each element generates heat by receiving radiation, and generates a displacement corresponding to the heat. An optical readout radiation-displacement converter having a plurality of one-dimensionally or two-dimensionally arranged elements for generating and emitting a received readout light with a change corresponding to the displacement and emitting the readout light; A readout optical system that irradiates readout light and forms an optical image corresponding to the displacement of each element based on the changed readout light emitted from each element, and the light readout type radiation-displacement converter. A sealed container for containing the radiation-transmitting window and the read-light transmitting window, wherein a temperature of a predetermined portion of the optical readout radiation-displacement converter is kept substantially constant. Low temperature for , A temperature sensor for directly or indirectly detecting the temperature of the predetermined portion of the optical readout radiation-displacement converter, and the optical readout radiation-displacement converter based on a detection signal from the temperature sensor. A temperature controller for controlling the temperature stabilizer so that the temperature of the predetermined portion of the converter is kept substantially constant.

The optical readout type radiation-displacement converter includes, for example, a base, a supported part supported by the base, a radiation absorption part receiving radiation and converting it to heat, and a radiation absorption part. A supported portion having a displacement portion that is displaced with respect to the base in accordance with the generated heat, and receives a readout light;
And a light action section for giving a change to the received readout light in accordance with the displacement of the displacement section to emit the changed readout light, and the supported portion and the light action section constitute one element. May be configured.

In this case, the supported portion may be electrically insulated from the base. The displacement section may constitute a cantilever or a diaphragm. Also,
The displacement portion may have at least two layers of different materials having different coefficients of expansion overlapping each other.
The radiation absorbing section may form at least a part of the displacement section. Alternatively, the radiation absorbing section may be fixed to the base regardless of the displacement of the displacement section, and the displacement section and the radiation absorbing section may be thermally coupled. The light acting part may be a reflecting part that forms a part of the supported part and that is displaced in accordance with the displacement of the displacement part, and that reflects the received read light. in this case,
The readout optical system divides the light from the light source into a plurality,
One of the divided lights is radiated as the readout light to the reflecting portions of the respective elements as the readout light, and each of the reflected lights emitted from the reflecting portions of the respective elements and the other of the divided lights May be made to interfere with each other to obtain interference light, and an optical image may be formed by the interference light. Further, the light acting section may be an interference unit that receives the readout light, converts the received readout light into interference light having an interference state corresponding to the displacement of the displacement section, and emits the same. The interference means is a half mirror part that forms a part of the supported part and is displaced in accordance with the displacement of the displacement part. The half mirror part reflects only a part of the received read light; And a reflector fixed to the base so as to face the substrate.

The optical readout radiation-displacement converter includes, for example, a base, a first supported part supported by the base, and a radiation absorption part receiving radiation and converting the radiation into heat. A first supported portion having a first displacement portion that is displaced with respect to the base in response to heat generated in the radiation absorbing portion; and a second supported portion supported by the base. A second supported portion having a second displacement portion that is displaced with respect to the base in accordance with heat received from the base; receiving a readout light; And a light action section for giving a change in accordance with the relative displacement between the second displacement section and emitting the changed readout light, wherein the first displacement section responds to an increase or decrease in heat. And the second displacement direction is substantially the same direction, and the first supported Parts, or may be constituted one element by said second supported portion and the optical action section.

[0024] In this case, each of the first displacement portion and the second displacement portion may have at least two layers of different materials having different coefficients of expansion overlapping each other.
The light acting section may be an interference unit that receives the readout light, converts the received readout light into interference light having an interference state corresponding to the relative displacement, and emits the light. This interference means forms a part of one of the first supported portion and the second supported portion, and according to the displacement of one of the first displacement portion and the second displacement portion. A displacing half mirror part, which forms a part of the other of the first supported part and the second supported part, and a half mirror part that reflects only a part of the received read light; A reflecting portion that is displaced in accordance with the other displacement of the first displacement portion and the second displacement portion, and that is disposed to face the half mirror portion. Good.

Further, the optical readout radiation-displacement converter includes a base, a first supported part supported by the base, and a radiation absorbing part that receives radiation and converts the radiation into heat. A first supported portion having a displacement portion that is displaced with respect to the base in accordance with heat generated in the absorbing portion; and a second supported portion supported by the base, the heat being increased or decreased. A second supported portion having a displacement suppressing portion that suppresses displacement of the displacement portion in an opposite direction to the displacement direction of the displacement portion with respect to heat from the base; A light acting portion for giving a change to the received read light in accordance with the displacement of the displacement portion and emitting the changed read light, wherein the first supported portion and the second One element is constituted by the supporting portion and the light acting portion. It may be.

In this case, the displacement suppressing section may be mechanically coupled to the displacement section via a coupling section having a large thermal resistance. Each of the displacement portion and the displacement suppression portion may include at least two layers of different materials having different coefficients of expansion that overlap with each other. The light acting section,
The reflecting portion may be a reflecting portion that forms a part of the first supported portion and that is displaced according to the displacement of the displacement portion, and that reflects the received readout light. Alternatively, the light acting unit may be an interference unit that receives the readout light, converts the received readout light into interference light having an interference state corresponding to the displacement of the displacement unit, and emits the same. The interference unit is a half mirror unit that forms a part of the first supported portion and that is displaced in accordance with the displacement of the displacement unit.
A half mirror unit that reflects only a part of the received read light and a reflecting unit fixed to the base so as to face the half mirror unit may be provided.

[0027] Further, the imaging device according to the first aspect may include imaging means for imaging the optical image. Further, for example, a Peltier element can be used as the temperature stabilizer.

According to the imaging apparatus of the first aspect, radiation such as infrared rays, X-rays, and ultraviolet rays is applied to each element of the optical readout type radiation-displacement converter, and the radiation is converted into heat in each element. It is converted and displaced according to the generated heat. That is, the incident radiation is converted into a displacement according to the amount. On the other hand, the readout optical system irradiates each element of the optical readout type radiation-displacement converter with readout light of visible light or other light. Each element gives the received readout light a change in accordance with the displacement and emits the readout light, so that the radiation applied to each element is converted into a change in the readout light. Then, an optical image corresponding to the displacement of each element is formed by the readout optical system based on the changed readout light. As a result, a radiation image is formed as an optical image. This optical image can be observed with the naked eye as it is, or can be imaged by an imaging device. Since displacement detection by light can be performed with high sensitivity, according to the imaging device according to the first aspect,
The radiation can be detected with high sensitivity, and thus an image of the radiation can be formed with high sensitivity. Further, in the imaging apparatus according to the first aspect, unlike the above-described conventional thermal infrared detector, the radiation is not converted into a resistance value (electric signal) through heat, but the radiation is converted through heat and displacement. Since the light is converted into a change in the reading light, it is not necessary to supply a current to each element, and each element does not generate heat. Therefore,
According to the first imaging device, since heat is detected only by incident radiation, a radiation image can be formed with high detection accuracy. Needless to say, the imaging apparatus does not require a cooler which is necessary in the quantum infrared detector, as in the above-described conventional thermal infrared detector. Further, since the imaging apparatus does not read out radiation as an electric signal, the readout circuit for a weak electric signal which is required in the above-described conventional thermal infrared detector is not required.

In the imaging device according to the first aspect, the optical readout radiation-displacement converter is housed in a sealed container, and the temperature sensor is provided in a predetermined portion of the optical readout radiation-displacement converter (described above). In each of the examples of the optical readout radiation-displacement converter described above, the temperature of the substrate is detected, and the temperature controller controls the temperature stabilizer based on the detection signal from the temperature sensor, thereby obtaining the optical readout type radiation-displacement converter. The temperature of said predetermined portion of the radiation-to-displacement converter is kept substantially constant. Therefore, even if the environmental temperature outside the container changes, the temperature of a predetermined portion of the optical readout radiation-displacement converter is kept constant. , Without depending on the ambient temperature, it depends only on the intensity of the incident radiation. Therefore, according to the first aspect, a stable radiation image can be obtained regardless of a change in the environmental temperature.

An imaging device according to a second aspect of the present invention comprises:
In the imaging device according to the first aspect, the space in the container is 1 atm or less or substantially evacuated.

As in the second embodiment, when the space in the container is reduced to 1 atm or less or substantially evacuated, the fluctuation of the container temperature which changes depending on the environmental temperature causes the light motion through the thermal motion of the gas molecules. Since the amount transmitted to the read-out type radiation-to-displacement converter is reduced or eliminated, the temperature of the optical read-out type radiation-to-displacement converter can be further stabilized, and a more stable radiation image can be obtained, which is preferable.

An imaging device according to a third aspect of the present invention comprises:
In the imaging device according to the second aspect, a gas molecule adsorbent is provided in the container.

Even if the space in the container is once evacuated, the degree of vacuum in the container decreases as time elapses due to outgassing from the surface of the components contained in the container. Therefore, as the time elapses, the amount of fluctuation of the container temperature that changes depending on the environmental temperature is transmitted to the optical readout radiation-displacement converter via the thermal motion of the gas molecules in the container, and the amount obtained is increased. The stability of the radiation image is slightly reduced. In this regard, when the gas molecule adsorbent is provided in the container as in the third aspect, the outgas or the like is adsorbed by the gas molecule adsorbent, so that the degree of vacuum in the space in the container is held semipermanently, preferable.

An imaging device according to a fourth aspect of the present invention comprises:
In the imaging device according to any one of the first to third aspects, the temperature stabilizer is housed in the container.

When the temperature stabilizer is housed in the container as in the fourth embodiment, the thermal load on the temperature stabilizer is reduced, and thus the temperature control with good responsiveness becomes possible. Therefore,
This is preferable because the temperature of the optical readout radiation-displacement converter can be accurately maintained at a constant temperature.

An imaging device according to a fifth aspect of the present invention comprises:
The imaging device according to any one of the first to fourth aspects, wherein the heat is thermally coupled to the temperature stabilizer and reduces transmission of unnecessary heat energy to the optical readout radiation-displacement converter. A shield is provided in the container.

When a heat shield is provided in the container as in the fifth embodiment, an optical readout type radiation-to-displacement converter for emitting unnecessary infrared rays and the like emitted from the container due to the container temperature changing depending on the environmental temperature. This is preferable because the background radiation energy incident on the light-emitting type radiation-displacement converter can be kept at a constant temperature with higher accuracy.

[0038]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, an imaging device according to the present invention will be described with reference to the drawings. In the following description, an example will be described in which the radiation is infrared light and the readout light is visible light. However, in the present invention, the radiation may be X-rays, ultraviolet rays, or other various radiations other than infrared light, May be other light than visible light.

(First Embodiment) First, an imaging apparatus according to a first embodiment of the present invention will be described with reference to FIG. FIG. 1 is a schematic configuration diagram showing an imaging device according to the present embodiment.

In the imaging apparatus according to the present embodiment, each element generates heat by receiving radiation, generates a displacement corresponding to the heat, and changes the received readout light j to a change corresponding to the displacement. Optical readout type radiation-displacement converter 1 having a plurality of one-dimensional or two-dimensionally arrayed elements for giving and emitting
00, and a readout optical system 101 that irradiates each element with the readout light j and forms an optical image corresponding to the displacement of each element based on the changed readout light emitted from each element. Have. Optical readout radiation
The displacement transducer 100 is housed in a sealed container 102.

The container 102 has a window 102a for transmitting the infrared light i on the incident side of the infrared light i, and a window 102b for transmitting the read light j on the incident side of the read light j. The window 102a is preferably made of a material having a filter function of transmitting infrared rays i such as Ge and cutting other unnecessary light. Similarly, as the window 102b,
It is preferable to use a filter that transmits the reading light j and cuts other unnecessary light. The portion of the container 102 other than the windows 102a and 102b can be made of, for example, a material such as copper, stainless steel, aluminum, or an alloy thereof.

In FIG. 1, reference numeral 103 denotes an exhaust pipe for evacuating a space 104 in the container 102 immediately after assembling the container 102. The exhaust pipe 103 is sealed after the space 104 is evacuated, and The space 104 is kept in a vacuum. However, in the present invention, the space 104 may be maintained at 1 atm or less, or an inert gas having a low thermal conductivity such as xenon gas may be sealed in the space 104. In the present embodiment, a gas molecule adsorbent 108 such as getter silica gel is provided in the container 102.

Also, the imaging device according to the present embodiment
Substrate 1 of optical readout radiation-displacement converter 100, which will be described later.
Temperature stabilizer 105 for keeping the temperature of the
have. As the temperature stabilizer 105, for example,
Peltier elements can be used. In the present embodiment, the temperature stabilizer 105 is housed in the container 102, and the optical readout radiation-displacement converter 10 is connected via the heat transfer plate 106.
0 substrate 1. However, in the present invention, the temperature stabilizer 105 may be arranged outside the container 102. Note that the temperature stabilizer 105 is arranged so as not to impede the incidence of the readout light j as shown in FIG.

Further, the imaging apparatus according to the present embodiment includes a temperature sensor 107 for detecting the temperature of the substrate 1 of the optical readout radiation-displacement converter 100, and the temperature sensor 107.
A temperature controller 109 for controlling the temperature stabilizer 105 so that the temperature of the substrate 1 of the optical readout type radiation-to-displacement converter 100 is kept substantially constant based on the detection signal from
And The temperature sensor 107 may use a separate element from the optical readout radiation-displacement converter 100, or when a silicon substrate is used as the substrate 1 of the optical readout radiation-displacement converter 100, For example, the substrate 1 may be formed as a resistance bolometer. Also,
The temperature sensor 107 does not directly detect the temperature of the substrate 1 of the optical readout radiation-displacement converter, but indirectly detects the temperature of the substrate 1 by detecting the temperature of the heat transfer plate 106, for example. You may do so. Temperature controller 10
Reference numeral 9 denotes the amount of current flowing through the Peltier element as the temperature stabilizer 105 based on the detection signal from the temperature sensor 107 so that the temperature of the substrate 1 becomes an arbitrarily set target temperature near the ambient temperature, for example. Control.

Further, as shown in FIG. 1, the imaging apparatus according to the present embodiment is thermally coupled to the temperature stabilizer 105, and transfers unnecessary heat energy to the optical readout radiation-displacement converter 100. Heat shield 110 to reduce transmission
Are provided in the container 102. Heat shield 110
Is made of a material having a high thermal conductivity, and is thermally coupled to the temperature stabilizer 105 via the heat transfer plate 106 in the present embodiment.

In FIG. 1, reference numeral 111 denotes an infrared imaging lens for forming an infrared image.

Next, the optical readout radiation-displacement converter 100 used in the imaging device according to the present embodiment will be described with reference to FIG.

FIG. 2 is a view showing the optical readout radiation-displacement converter 100. FIG. 2A is a schematic cross-sectional view of a unit pixel (unit element) in a state where infrared rays i are not incident. FIG. 2B is a diagram schematically showing a cross section of the unit pixel in a state where the infrared ray i is incident, and FIG.
FIG. 2A is a plan view showing the arrangement state of the pixels, and is a plan view corresponding to FIG. 2C, taken along the line AA ′ in FIG.

The radiation-to-displacement converter 100 includes a substrate 1 as a base, and a supported portion 3 supported on the substrate 1 via legs 2 so as to be floated.

In the present embodiment, the supported portion 3
Is provided so that the infrared light i is incident from below the substrate 1 and the readout light j is incident from above the substrate 1. Therefore, the substrate 1 is made of a material that transmits the infrared light i. I have. Specifically, a silicon substrate, a Ge substrate, or the like can be used as the substrate 1. However, when the reading light is incident from below the substrate 1 and the infrared light i is incident from above the substrate 1, the substrate 1 may be made of a material that transmits the reading light. However, the material of the substrate 1 is not limited at all if an opening is formed in a desired region of the substrate 1 where infrared light or readout light passes (region L1 in FIG. 2A).

The supported part 3 is composed of two films 4 and 5 which are overlapped with each other. The lower film 4 is an infrared absorbing portion that receives infrared rays and converts them into heat. The film 4 and the film 5 are made of different materials having different expansion coefficients, and constitute a so-called thermal bimorph structure. Therefore, in the present embodiment, the films 4 and 5 cause the substrate 1 to respond to the heat generated in the film 4 as the infrared absorbing portion.
Constitutes a displacement portion that is displaced with respect to. As described later, since the films 4 and 5 constitute a cantilever, when the expansion coefficient of the lower film 4 is larger than the expansion coefficient of the upper film 5, as shown in FIG. It is curved upward and inclined. Conversely, the expansion coefficient of the lower film 4 may be smaller than the expansion coefficient of the upper film 5, and in this case, the heat causes the film to curve downward and tilt. Further, in the present embodiment, the upper film 5 constitutes a reflecting portion for reflecting the readout light j, receives the readout light j, and changes the received readout light according to the displacement of the displacement portion. This constitutes a light acting section for emitting the changed readout light. That is, the film 5 as the reflecting portion receives the readout light j and gives the received readout light a change in the reflection direction and the change in the reflection position in accordance with the displacement of the films 4 and 5 as the displacement portions. The readout light is emitted as reflected light.

As can be seen from the above description, in the present embodiment, the film 4 also serves as a part of the displacement part and the infrared absorbing part, and the film 5 is used as the other part of the displacement part and the read-out as the light acting part. The light reflector is also used. In other words, the infrared absorption part forms a part of the displacement part, and the readout light reflection part forms a part of the displacement part. Therefore, the structure is simple and inexpensive. In the present embodiment, the film 5, which is the readout light reflecting portion as the light acting portion, naturally forms a part of the supported portion 3 and is displaced in accordance with the displacement of the displacement portion. In the present embodiment, the material of the film 4 is, for example, gold black, ceramics (for example, ZrO ₂ , MnO ₂ ,
FeO ₃ , CoO, CuO, Al ₂ O ₃ , MgO, SiO ₂
, A positive resist, a negative resist, graphite (carbon), SiN, or the like. Examples of the material of the film 5 include Al, Ag, and Mg.
O and the metals listed in Table 1 described below can be used.

However, the infrared absorbing section may be used as a part of the displacement section, and the readout light reflection section may be independent of the displacement section. In this case, for example, the supported portion 3
Is formed by laminating three films, the lower film is made of the same material as the film 4, the upper film is made of the same material as the film 5, and the intermediate film is the lower film. The film may be made of a material having an expansion coefficient different from that of the material of the film. Also,
The infrared absorbing section may be independent of the displacement section, and the readout light reflection section may also be used as a part of the displacement section. In this case, for example, the supported portion 3 is formed by stacking three films, the lower film is formed of the same material as the film 4, and the upper film is formed of the same material as the film 5. In this case, the intermediate film may be made of a material having an expansion coefficient different from that of the material of the upper film. Further, the infrared absorbing section may be independent of the displacement section, and the readout light reflecting section may be independent of the displacement section. In this case, for example, the supported portion 3 is formed by stacking four films, the lowermost film is formed of the same material as the film 4, and the uppermost film is formed of the same material as the film 5. The two intermediate films may be made of different materials having different coefficients of expansion. As a material of the intermediate two films, for example, a metal material known as a bimetal material may be used.

In this embodiment, as shown in FIG. 2, one end of the supported portion 3 is supported by the substrate 1 via the leg portion 2 so that the supported portion 3 separates the gap 6 from the substrate 1. It has a structure floating apart, and the displacement part composed of the films 4 and 5 constitutes a cantilever. However, the displacement part may constitute a diaphragm. Since the supported portion 3 floats from the substrate 1 in this manner, the thermal resistance between the supported portion 3 and the substrate 1 is increased. Furthermore, in the present embodiment, the leg 2 is made of an insulating material such as SiO _2, and the part to be supported 3 and the substrate 1 are electrically insulated. Since such an insulating material has a low thermal conductivity and a large thermal resistance, the thermal resistance between the supported portion 3 and the substrate 1 is further increased. Therefore, it is difficult for the thermal energy to escape from the supported portion 3, and the temperature of the film 4 is increased even by the slight incidence of infrared light, and the infrared light detection sensitivity is increased.

In this embodiment, as shown in FIG. 2D, the films 4 and 5 and the legs 2 are used as unit pixels (unit elements), and the pixels are two-dimensionally arranged on the substrate 1. I have.
Needless to say, the pixels may be arranged one-dimensionally on the substrate 1 as necessary, or if only the intensity of radiation is to be detected, only a single pixel may be arranged on the substrate 1. You may. This applies to the converter shown in FIG. 4 described later, the converters shown in FIGS. 6 and 7, and the converters shown in FIGS. 8 and 9.

The optical readout radiation-displacement converter 100 having the above-described structure can be manufactured by using, for example, a semiconductor manufacturing process.

According to the above described optical readout radiation-displacement converter 100, the infrared rays i are incident from below in FIG. The infrared light i is transmitted through the substrate 1 and is absorbed by the film 4 also serving as an infrared absorbing portion, and is converted into heat. FIG.
As shown in (b), the films 4 and 5, which also serve as displacement parts, are curved upward and inclined in accordance with the heat generated in the film 4. That is, the incident infrared rays i are converted into displacements of the films 4 and 5 according to the amount. On the other hand, a readout optical system, which will be described later, causes a readout light j of visible light to be incident from above in FIG. Since the film 5 changes the reflection direction and the reflection position according to the displacement and emits the changed read light as reflected light,
As a result, the infrared light applied to the film 4 is converted into a change in the reflected light of the reading light. Therefore, as described later, infrared light can be detected based on the reflected light of the read light reflected by the film 5. At this time, since displacement detection by light can be performed with high sensitivity, according to the present embodiment, infrared rays can be detected with high sensitivity, and an infrared image can be formed with high sensitivity. . Further, in the present embodiment, the infrared ray is not converted into a resistance value (electric signal) through heat, but is converted into a change in readout light through heat and displacement.
There is no need to supply an electric current to the supported portion 3 supported by the above, and self-heating does not occur in the supported portion 3. Therefore,
According to the present embodiment, since heat is detected only by incident infrared light, S / N is improved, detection accuracy is improved, and an infrared image can be formed with high detection accuracy. Needless to say, in the present embodiment, the cooler that was required in the quantum infrared detector is not required. Further, in the present embodiment, since infrared light is not read out as an electric signal, a readout circuit for a weak electric signal which is necessary in a conventional thermal infrared detector becomes unnecessary.

Next, the optical configuration of the imaging device according to the present embodiment will be described with reference to FIG. FIG. 3 is a schematic configuration diagram showing an optical configuration of the imaging device according to the present embodiment. In FIG. 3, the same components as those in FIG. 1 are denoted by the same reference numerals. In FIG. 3, the container 102 and the like are omitted.

In the present embodiment, the readout optical system 1
01 irradiates the readout light j to the film 5 as a reflecting portion of each element (pixel) of the converter 100, and based on the reflected light of the readout light reflected by the film 5 of each element, It is configured to form an optical image according to the displacement of the films 4 and 5 as the displacement parts of the element.
As shown in FIG. 3, a white light source 24 such as a white lamp, lenses 25, 26, 27, 28, beam splitters 29, 3
0, a total reflection mirror 31, an R light reflection dichroic mirror 32, and a B light reflection dichroic mirror 33. Although not shown in FIG. 1, the imaging device according to the present embodiment has two-dimensional CCDs 21 and 22 as imaging means for capturing an optical image formed by readout optical system 101, as shown in FIG. , 23 are provided.

In this embodiment, the readout optical system 101
Are configured to form the optical image using interference. The surface of the converter 100 on which the film 5 as a reflection part is distributed and the light receiving surfaces of the CCDs 21 to 23
Regarding 5, 26 to 28, they are arranged at positions conjugate to each other. The CCDs 21 to 23, the lenses 26 to 28, and the dichroic mirrors 32 and 33 constitute a three-plate type visible light CCD camera. Note that an illumination lens may be appropriately disposed between the white light source 24 and the beam splitter 29.

In the present embodiment, the infrared rays i are condensed by the imaging lens 111 and an infrared image is formed on the surface of the converter 100 where the film 4 as the infrared absorbing portion is distributed. As a result, as described above, the films 4 and 5 of each pixel are displaced according to the amount of the incident infrared rays on the film 4 of each pixel of the converter 100.

On the other hand, the light emitted from the white light source 24 is reflected by the beam splitter 29, reaches the beam splitter 30 via the lens 25, passes through the beam splitter 30, and irradiates the converter 100 with the read light. The total reflection mirror 31 reflected by the beam splitter 30
And the reference light traveling toward. The read light applied to the converter 100 is reflected by the film 5 of each pixel of the converter 100, passes through the beam splitter 30, and travels to the lens 25. On the other hand, the reference light is reflected by the total reflection mirror 31, further reflected by the beam splitter 30, and travels to the lens 25. Therefore, the read light reflected by the film 5 of each pixel and the reference light reflected by the total reflection mirror 31 are combined by the beam splitter 30. The two combined lights are strengthened or weakened according to the phase difference based on the principle of interference to become interference light. For this reason, this interference light has a light intensity of a distribution whose spectral distribution is shifted from the original white light source 24 according to the displacement amount of the film 5 of each pixel of the converter 100 (that is, each pixel has 3 has a distribution of interference colors according to the amount of displacement of the film 5), passes through the lens 25 from the beam splitter 30 to the right in FIG. 3, and further passes through the beam splitter 29. The interference light transmitted through the beam splitter 29 is color-separated by dichroic mirrors 32 and 33, an optical image of the R light component of the interference light is formed on the CCD 22 via the lens 27, and An optical image of the B light component is formed on the CCD 23 via the lens 28, and an optical image of the G light component of the interference light is formed on the CCD 21 via the lens 26.
An image is taken by 2, 23. Thus, the incident infrared image is converted into a visible image, and the visible image is captured.

In the present embodiment, the visible image is picked up by the CCDs 21, 22, and 23. However, the visible image may be observed with the naked eye. In this case, for example, in FIG. 3, dichroic mirrors 32 and 33,
Remove the lenses 27 and 28 and the CCDs 21 to 23,
What is necessary is just to observe the visible image formed in the position of CD21 with the naked eye.

In place of the white light source 24, a monochromatic light source such as a laser may be used. In this case, since an interference image having a distribution of a change in intensity corresponding to the displacement of the film 5 of each pixel of the converter 100 at that wavelength can be obtained, a monochrome CCD camera may be used. Specifically, for example, in FIG. 3, dichroic mirrors 32 and 33,
The lenses 27 and 28 and the CCDs 22 and 23 may be removed. Also in this case, the CCD 21 is removed and the CCD 2 is removed.
The monochromatic visible image formed at the position 1 may be observed with the naked eye. Note that, instead of the white light source 24, two light sources having different wavelengths are used.
When a light source that emits a single type of monochromatic light is used, an optical path length difference can be determined even in the case of interference that is not understood by monochromatic light and that is shifted by one or more cycles.

If the displacement range of the films 4 and 5 is not limited as the displacement portion of the converter 100, the intensity of interference is such that the difference in optical path length repeats the intensity every half of the wavelength of the readout light. When an infrared ray having a higher intensity is incident, an inversion phenomenon occurs in which the intensity of the interference is inverted. Therefore, it is preferable to limit the range of the displacement of the films 4 and 5 to 以下 or less of the wavelength of the reading light so that the change of the interference intensity due to the displacement of the films 4 and 5 becomes monotonous. For example, if the films 4 and 5 are bent downward in FIG. 2A when the temperature rises, and the distance between the film 4 and the upper surface of the substrate 1 is set to 1/4 or less of the wavelength of the read light, Even if excessive infrared rays are incident, the movement of the films 4 and 5 stops at the point where the free end of the film 4 and the upper surface of the substrate 1 are in contact. Note that the total reflection mirror 31 needs to be positioned at an appropriate position. The above is the light source 24
In the case where a white light source is used as the light source 24, similarly, the change of the interference color due to the displacement of the films 4 and 5 becomes a monotonous change. What is necessary is just to limit the range of displacement. Needless to say, a special restricting portion for restricting the range of displacement of the films 4 and 5 may be provided.

Note that a commercially available interference objective lens may be used instead of the lens 25 and the total reflection mirror 31.

As described above, according to this embodiment, a radiation image can be visualized with high detection accuracy and sensitivity without the need for a cooler.

In the imaging apparatus according to the present embodiment, the converter 100 is housed in the sealed container 102, the temperature sensor 107 detects the temperature of the substrate 1 of the converter 100, and the temperature controller 109 By controlling the temperature stabilizer 105 based on the detection signal from the temperature sensor 107, the temperature of the substrate 1 of the converter 100 is kept substantially constant. Therefore, even if the environmental temperature outside the container 102 changes, the temperature of the substrate 1 of the converter 100 is kept constant, so that the displacement generated in each element (pixel) of the converter 100 is affected by the environmental temperature. Without depending on the intensity of the incident infrared light i. Therefore, according to the present embodiment, a stable infrared image can be obtained irrespective of a change in environmental temperature.

Also, in this embodiment, since the space 104 in the container 102 is evacuated, the temperature fluctuation of the container 102 that changes depending on the environmental temperature causes the optical readout via the thermal motion of the gas molecules. Since it is not transmitted to the type radiation-displacement converter, the temperature of the substrate 1 of the converter 100 can be further stabilized, and a more stable radiation image can be obtained, which is preferable. However, in the present invention, the space 104 does not necessarily have to be evacuated.

Even if the space 104 in the container 102 is once evacuated, if the gas molecule adsorbent 108 is not provided in the container 102, the outgassing from the surface of the component housed in the container 102 or the like will cause the subsequent time. , The degree of vacuum in the container 102 decreases. Therefore, as the time elapses, the container 102 changes depending on the environmental temperature.
The amount of the temperature fluctuation transmitted to the converter 100 via the thermal motion of the gas molecules in the container 102 increases, and the stability of the obtained infrared image slightly decreases. In this regard, according to the present embodiment, since the gas molecule adsorbent 108 is provided in the container 102, the outgas or the like is adsorbed by the gas molecule adsorbent 108, so that the space 104 in the container 102 The degree of vacuum is held semi-permanently,
preferable.

Further, according to the present embodiment, since the temperature stabilizer 105 is housed inside the container 102 instead of outside the container 102, the heat load of the temperature stabilizer 105 is reduced. Temperature control with good responsiveness becomes possible. Therefore, the temperature of the substrate 1 of the converter 100 can be accurately maintained at a constant temperature, which is preferable.

Even if the space 104 in the container 102 is evacuated, if the temperature of the container 102 fluctuates due to a change in environmental temperature, the amount of infrared radiation emitted from the container 102 fluctuates,
The temperature of converter 100 may fluctuate. However, according to the present embodiment, the heat shield 110
Is provided, unnecessary infrared rays incident on the converter 100 are eliminated as much as possible, and the temperature of the converter 100 can be more accurately maintained at a constant temperature, which is preferable.

(Second Embodiment) Next, a second embodiment of the present invention will be described.
FIGS. 4 and 5 show the imaging device according to the embodiment.
This will be described with reference to FIG.

FIG. 4 is a view showing an optical readout type radiation-to-displacement converter used in the imaging apparatus according to the present embodiment, and FIG. 4 (a) is a partially cutaway plan view schematically showing the converter. 4 (b) is a view taken along the line BB 'in FIG. 4 (a). FIG. 5 is a schematic configuration diagram showing an optical configuration of the imaging device according to the present embodiment.

The imaging apparatus according to the present embodiment differs from the imaging apparatus according to the first embodiment only in the configuration of the converter 100 and the configuration of the readout optical system 101 in FIG. Duplicate description of other parts is omitted.

In the imaging device according to the present embodiment, FIG.
The converter shown in FIG. 4 is used as the converter 100 in FIG.

The converter shown in FIG.
01 and a supported portion 203 supported on the substrate 201 via the leg portion 202 in a floating state.

In the present embodiment, the supported portion 203 is provided on the substrate 201, and infrared rays i are incident from below the substrate 201, and read light j is emitted from above the substrate 201.
₀ is incident, the substrate 201
Is made of a material that transmits infrared rays i. Specifically, as the substrate 201, a silicon substrate, a Ge substrate, or the like can be used. However, when the reading light j ₀ from below the substrate 201 infrared i is incident from above the substrate 201 while being incident, a material that transmits readout light it is sufficient to constitute the substrate 201. In this case, for example, an infrared absorption film
The half mirror unit 208 described later is formed on the upper surface of the
9 may be a half mirror. However, the substrate 201
The material of the substrate 201 is not limited in any way as long as an opening is formed in a desired region through which infrared light or readout light passes.

The supported portion 203 is composed of two overlapping films 204 and 2 made of different materials having different expansion coefficients.
05. The films 204 and 205 constitute a so-called thermal bimorph structure. The films 204 and 205 may be made of arbitrary materials having different expansion coefficients.
For example, as a material of the films 204 and 205, a metal material known as a bimetal material may be used. On the lower surface of the lower film 204, an infrared absorbing film 207 made of the same material as the film 4 in FIG. 2 such as gold black is formed. In the present embodiment, the films 204 and 205 constitute a displacement unit 206 that displaces with respect to the substrate 201 according to heat generated in the infrared absorption film 207. Since the displacement portion 206 forms a cantilever as described later, when the expansion coefficient of the lower film 204 is larger than the expansion coefficient of the upper film 205, the heat is curved upward and inclined by the heat, When the expansion coefficient of the film 204 is smaller than the expansion coefficient of the upper film 205, the film 204 is curved downward and inclined by the heat.

As in the case of the optical readout type radiation-to-displacement converter shown in FIG. 2, a single film may be used as the film 204 and the infrared absorption film 207 which form a part of the displacement section 206.

[0081] The supported portion 203 has also a half mirror 208 which reflects only a portion of the read-out light j _0. The half mirror unit 208 is fixed to the free end side of the displacement unit 206, and is displaced according to the displacement of the displacement unit 206. An area on the substrate 201 facing the half mirror section 208 is provided with the half mirror section 20.
A total reflection mirror 209 is formed as a reflection unit that reflects the readout light transmitted through the mirror 8.

As shown in FIG. 4B, the read light j ₀
There made incident on the half mirror unit 208, the read light j part becomes reflected light j ₁ is reflected by the half mirror 208 of _0, the remaining reading light j ₀ incident on the half mirror 208 a half mirror 208 And is reflected by the total reflection mirror 209 and again enters the half mirror unit 208 from the lower surface. Part of the readout light that has reentered the half mirror unit 208 from the lower surface is partially reflected by the half mirror unit 2
08 transmitted the transmitted light j ₂ a. Between the transmitted light j ₂ and the reflected light j _1, there is an optical path length difference corresponding to twice the spacing d1 between the half mirror 208 and the total reflection mirror 209. Therefore, interference occurs in response to the optical path length difference between the reflected light j ₁ and transmitted light j _2, the reflected light j ₁ and transmitted light j ₂
Is an interference light having an interference intensity corresponding to the optical path length difference (according to the displacement of the displacement unit 206), and is emitted from the half mirror unit 208. Since the interference intensity of the interference light and the intensity of the transmitted light j ₂ and the intensity of the reflected light j ₁ is strongest when equal, the half mirror unit 2
It is desirable to make the reflectivity of 08 about 38%.

As can be seen from the above description, in the present embodiment, the half mirror unit 208 and the total reflection mirror 209
But receives the reading light j _0, constitute an interference means to be emitted instead of the interference light which has an interference state corresponding to the reading light j ₀ which has received the displacement of the displacement portion 206, and thus,
Receiving the reading light j _0, constitute the optical action section for emitting a reading light the change giving change corresponding to the displacement of the displacement portion 206 to the read beam j ₀ that is received.

In this embodiment, as shown in FIG. 4, one end of the supported portion 203 is connected to the substrate 2 via the leg portion 202.
01 supported on the substrate 20
It has a structure that floats from a gap 1 with a gap 210 therebetween, and the displacement portion 206 composed of the films 204 and 205 constitutes a cantilever. In this manner, the supported portion 203 is
, The thermal resistance between the supported portion 203 and the substrate 201 is large. Further, in the present embodiment, the leg portion 202 is made of an insulating material such as SiO _2, and the portion to be supported 203 and the substrate 201 are electrically insulated. Such an insulating material has a low thermal conductivity and a high thermal resistance.
The thermal resistance between them is larger. Therefore, it is difficult for heat energy to escape from the supported portion 203, and the temperature of the infrared absorbing film 207 is increased even by a slight incidence of infrared light, and the infrared light detection sensitivity is increased.

In this embodiment, as shown in FIG. 4A, the displacement section 206, the infrared absorbing film 207, the half mirror section 208, the total reflection mirror 209, and the leg section 202 are used as unit pixels (unit elements). The pixels are two-dimensionally arranged on the substrate 201. However, if necessary, the pixels may be arranged one-dimensionally on the substrate 201, or if only the intensity of radiation is to be detected, only a single pixel may be arranged on the substrate 201. You may.

[0086] Further, converter used in this embodiment, have a mask 211 for masking the light other than interference light coming from the half mirror 208 constituting the light acting portion of the reading light j ₀ irradiated doing. Mask 211
Is an opening 211 in a region corresponding to the half mirror unit 208.
a. The mask 211 can be formed, for example, by applying black paint on the window 102b in FIG. 1 or by a film supported by the substrate 201. Although the interference light coming from the half mirror unit 208 of the reading light j ₀ to be irradiated is a signal light, the signal other than light of readout light (i.e., noise light) when the mix in the optical signal , So-called S / N is reduced. In this regard, according to the present embodiment, the mask 21
As a result, the noise light does not mix with the signal light, and the S / N is improved. However, the mask 21 is not necessarily
It is not necessary to provide 1.

The optical readout type radiation-to-displacement converter shown in FIG. 4 can also be manufactured by using a semiconductor manufacturing process.

According to the optical readout type radiation-to-displacement converter shown in FIG. 4 used in the present embodiment,
(B) Light is incident from below. The infrared light i is transmitted through the substrate 201, absorbed by the infrared absorbing film 207, and converted into heat. In response to the heat generated in the infrared absorbing film 207, the displacement portion 206 is curved upward or downward and inclined. That is, the incident infrared light i is converted into a displacement of the displacement unit 206 according to the amount. On the other hand, the reading optical system, which will be described later, the reading light j ₀ of the visible light, FIG. 4
The light is incident on the half mirror unit 208 from above in FIG. As a result, as described above, the readout light j ₀ incident on the half mirror 208 is varied in the interference light having an interference intensity corresponding to the displacement of the displacement portion 206, FIG. 4 the interference light from the half mirror 208 It is emitted above (b). Therefore, as described later, infrared rays can be detected based on the interference light.

When a metal material known as a bimetal is used as the films 204 and 205, the relative curvature K of the bimetal and the thickness d and the length L of the displacement portion 206 make 1 ° C. The displacement D of the free end when one end is fixed with respect to the temperature change can be calculated by the following equation (Equation 1).

[0090]

D = L ² × K / 2d

For example, when the length L is 20 μm and the thickness d is 0.
If the relative curvature K is 3 × 10 ⁻⁴ at 1 μm, the displacement D is 0.
6 μm. Furthermore, assuming that the conversion rate for receiving infrared rays emitted according to the temperature of the observation object and converting it into temperature is 1% as described above, the displacement of the bimetal is 6 nm.

As described above, between the transmitted light j ₂ and the reflected light j ₁ , there is an optical path length difference corresponding to twice the distance d 1 between the half mirror section 208 and the total reflection mirror 209. There, since thereby the interference occurs, for example, if the 500nm wavelength of the reading light j _0, interference 1/2
Since the intensity is repeated for each wavelength, the interval d1 is 125 nm
Repeat the strength every time it changes.

Therefore, the displacement 6 nm of the displacement portion 206 corresponds to 4.8% of the interference period 125 nm, which is much larger than the conventional resistance change of 0.02%.

In the present embodiment, since the technique for detecting a minute displacement called interference with high sensitivity is applied to the detection of infrared rays, it is possible to perform detection with higher sensitivity than before.
As a result, an infrared image can be formed with high sensitivity.

Further, in the present embodiment, similarly to the above-described first embodiment, the infrared rays are not converted into a resistance value (electric signal) through heat, but the infrared rays are read out through heat and displacement. Therefore, there is no need to supply a current to the supported portion 203 supported by the substrate 201, and self-heating does not occur in the supported portion 203. Therefore, according to the present embodiment, since heat is detected only by the incident infrared light, the S / N is improved, the detection accuracy is improved, and an infrared image can be formed with high detection accuracy. . Needless to say, in the present embodiment, the cooler that was required in the quantum infrared detector is not required. Further, in the present embodiment, since infrared light is not read out as an electric signal, a readout circuit for a weak electric signal which is necessary in a conventional thermal infrared detector becomes unnecessary.

By the way, the interference light is also obtained in the imaging apparatus according to the first embodiment described above, but as shown in FIG. 3, the interference light is used for the optical readout radiation-displacement converter shown in FIG. Obtained outside. Therefore, even if uniform infrared rays are incident on the optical readout radiation-displacement converter 100, the height of the reflection film 5 of each element varies due to the poor flatness of the substrate 1, or the reference light is reflected. If the flatness of the total reflection mirror 31 is not maintained, a signal in which the interference intensity varies for each element is generated even though uniform infrared rays are incident.

In this respect, in the present embodiment, the half mirror section 208 and the total reflection mirror 209 of each element constitute interference means, and are independently provided for each element inside the optical readout type radiation-displacement converter. Since the interference light can be obtained, the uniformity of the output signal of each element is extremely good. In the present embodiment, the optical readout radiation
Since there is no need to configure an interference optical system outside the displacement converter, the configuration of the readout optical system is simplified even when the readout optical system is configured according to the principle of interference.

If the displacement range of the displacement section 206 is not limited, the intensity of the interference repeats the intensity every half of the wavelength of the read light because of the difference in the optical path length. Conversely, an inversion phenomenon in which the interference intensity is inverted occurs. Therefore, it is preferable to limit the range of displacement of the displacement unit 206 to 以下 or less of the wavelength of the read light so that the change in the interference intensity due to the displacement of the displacement unit 206 becomes a monotonous change. For example, if the displacement section 206 is bent downward in FIG. 4B when the temperature rises, and the interval between the half mirror section 208 and the total reflection mirror 209 is set to be 1/4 or less of the wavelength of the read light. However, even if excessive infrared rays are incident, the movement of the displacement unit 206 stops at the point where the half mirror unit 208 and the total reflection mirror 209 are in contact with each other.
At this time, since the interference intensity becomes maximum, the inversion phenomenon does not occur. The description so far is based on the case where monochromatic light is used as the readout light. However, even when white light is used as the readout light, similarly, the change of the interference color due to the displacement of the displacement unit 206 becomes a monotonous change. Then, the range of displacement of the displacement unit 206 may be limited. It is needless to say that a special restricting portion for restricting the range of displacement of the displacement portion 206 may be provided.

In this embodiment, the readout optical system shown in FIG. 5 is used as the readout optical system 101 in FIG.

[0100] In this embodiment, the read optics converter shown in FIG. 4 (in FIG. 5, denoted by reference numeral 100) the respective half-mirror portion 208 the reading light j ₀ of the elements (pixels) of And is configured to form an optical image corresponding to the displacement of the displacement unit 206 of each element based on the interference light emitted from the half mirror unit 208 of each element, and specifically, As shown in FIG.
41, aperture 242 (alternatively, an illumination lens may be used), beam splitter 243, lenses 244, 2
45.

In the present embodiment, infrared rays i are condensed by the imaging lens 111 and an infrared image is formed on the surface of the converter shown in FIG. 4 where the infrared absorbing film 207 is distributed. As a result, the infrared absorbing film 2 of each pixel of the converter 100
The displacement unit 206 of each pixel is displaced in accordance with the amount of incident infrared rays with respect to 07.

[0102] On the other hand, light emitted from the light source 241 is reflected by the beam splitter 243 and enters the converter shown in FIG. 4 as a reading light j ₀ through lens 244. As a result, interference light having an interference intensity corresponding to the displacement of the displacement unit 206 of each element (pixel) is generated by the half mirror unit 20 of each element.
8 to the lens 244, and this interference light is
Lens 244, beam splitter 243, and lens 24
5, an optical image is formed by the interference light, and this is observed with the naked eye 246. In this way, the incident infrared image is converted into a visible image.

Note that instead of observation with the naked eye 246, 2
The optical image may be captured by arranging a dimensional CCD or the like.
In this case, sensitivity variations and offsets can be electrically corrected. Such a situation is the same in the other imaging devices described above. In addition, this CCD
Need not match the number of pixels of the converter shown in FIG. 4, but it is preferable that the number of pixels is approximately the same.

The reading optical system is not limited to the configuration shown in FIG. Since the converter shown in FIG. 4 causes interference inside, there is no need for an optical system for causing interference to the outside, and there is an optical system capable of simply supplying readout light for causing interference and observing the interference intensity. Is enough. The reading light is not limited to monochromatic light, but may be white light. In the case of white light, the interference intensity is observed as an interference color. Also, if two types of monochromatic light having different wavelengths are used as the readout light, the optical path length difference can be determined even in the case of interference that is not known by monochromatic light and is shifted by one or more cycles. A wide infrared image can be obtained.

In addition to the above, according to the present embodiment,
The same advantages as in the first embodiment can be obtained.

(Third Embodiment) Next, a third embodiment of the present invention will be described.
FIGS. 6 and 7 show the imaging device according to the embodiment.
This will be described with reference to FIG.

FIG. 6 is a diagram showing an optical readout type radiation-to-displacement converter used in the imaging apparatus according to the present embodiment. FIG. 6A shows a two-story structure of the unit pixel (unit element). FIG. 6B is a plan view schematically showing the second floor portion.
6 is a plan view schematically showing the first floor portion, FIG. 6C is a cross-sectional view taken along line CC ′ in FIGS. 6A and 6B, and FIG.
FIG. 6D is a cross-sectional view taken along line DD ′ in FIGS. 6A and 6B. FIG. 7 is a plan view showing an arrangement state of pixels of the optical readout radiation-displacement converter.

The imaging device according to the present embodiment differs from the imaging device according to the first embodiment only in the configuration of the converter 100 and the configuration of the readout optical system 101 in FIG. Duplicate description of other parts is omitted. The readout optical system used in the present embodiment is the same as the readout optical system shown in FIG. 5 used in the second embodiment.
A duplicate description of the reading optical system is omitted.

In the imaging apparatus according to the present embodiment, the converters shown in FIGS. 6 and 7 are used as converter 100 in FIG.

The converter shown in FIGS. 6 and 7 includes a substrate 301 as a base, a first supported portion 303 supported on the substrate 301 via legs 302, and a leg 3
And a second supported portion 305 which is supported on the substrate 301 via the first support portion 04. In the present embodiment, the first and second supported portions 303 and 305 form a two-story structure, in which the first supported portion 303 is a two-story portion and the second supported portion 305 is one. It is on the floor.

In this embodiment, the supported portions 303 and 305 are provided on the substrate 301 so that the infrared rays i are incident from below the substrate 301 and the reading light j ₀ is incident from above the substrate 301. As a result, the substrate 301 is made of a material that transmits infrared rays i. Specifically, as the substrate 301, a silicon substrate or G
An e-substrate or the like can be used. However, the substrate 30
When one of the read light j ₀ from below infrared i is incident with the upper side of the substrate 301 is incident, it is sufficient to constitute a substrate 301 of a material that transmits readout light j _0. However, if an opening is formed in a desired passage area of the infrared light or the readout light on the substrate 301, the substrate 3
The material No. 01 is not limited at all.

In the present embodiment, the first supported portion 303 of the second floor portion is directly fixed to the leg portion 302 and is disposed at the center and receives an infrared ray and converts it into heat.
A first displacement portion 307 having one end portion fixed to each of the infrared absorption films 306 and disposed on both sides of the infrared absorption film 306; and a first displacement portion 307 fixed to the free end side of each first displacement portion 307. has been arranged to surround the infrared ray absorbing film 306 in a U-shape, a half mirror 308 which reflects only a portion of the read-out light j _0, together with the displacement portion 307. The first displacement section 307 forms a cantilever. In the present embodiment, the infrared absorbing film 306 is thermally connected to the first displacement portion 307, but has a structure that does not move even if the first displacement portion 307 is displaced.

As a material of the infrared absorbing film 306,
For example, for example, gold black, ceramics (for example, ZrO
₂ , MnO ₂ , FeO ₃ , CoO, CuO, Al ₂ O ₃ , M
gO, SiO _2, etc.), a positive resist, a negative resist, graphite (carbon), SiN, or the like.

The first displacement section 307 is composed of two films 307a and 307b which are overlapped with each other. The films 307a and 307b are made of different materials having different expansion coefficients, and form a so-called thermal bimorph structure. Therefore, in the present embodiment,
The first displacement unit 307 is displaced with respect to the substrate 301 according to heat generated in the infrared absorbing film 306. Lower membrane 3
When the expansion coefficient of 07a is larger than the expansion coefficient of the upper film 307b, it is curved upward and inclined by the heat generated in the infrared absorbing film 306. Conversely, the expansion coefficient of the lower film 307a may be smaller than the expansion coefficient of the upper film 307b. In this case, the heat causes the film to curve downward and tilt.

The films 307a and 307b may be made of arbitrary materials having different expansion coefficients. For example, as a material of the films 307a and 307b, Al, Ag, Mg
O or a metal material known as a bimetal material can be used.

Since the supported portion 303 is floating from the substrate 301 as described above, the supported portion 303 and the substrate 3
01 is large. Further, in the present embodiment, the leg portion 302 is made of an insulating material such as SiO _2, and the portion to be supported 303 and the substrate 301 are electrically insulated. Such an insulating material has a low thermal conductivity and a high thermal resistance.
Thermal resistance between the substrate and the substrate 301 is further increased.
Therefore, it is difficult for heat energy to escape from the supported portion 303, and even if a small amount of infrared light is incident, the infrared absorbing film 30 can be used.
In No. 6, the temperature rises, and the infrared light detection sensitivity increases. In addition,
The leg 304 is also made of SiO ₂ or the like, like the leg 302.

In the present embodiment, the second supported portion 305 of the first floor portion has one end portion directly fixed to the leg portion 304 and is disposed below the first displacement portion 307 on each side. And the readout light transmitted through the half mirror unit 308 fixed to the free end side of each second displacement unit 309 and arranged in a U-shape with each second displacement unit 309. And a total reflection mirror 310 as a reflection unit for reflecting light. The total reflection mirror 310 faces the half mirror unit 308. 2nd displacement part 3
09 constitutes a cantilever. 2nd displacement part 3
Similarly to the first displacement portion 307, 09 is composed of two films 309a and 309b overlapping each other.
The films 309a and 309b are made of different materials having different expansion coefficients, and form a so-called thermal bimorph structure. Therefore, in the present embodiment, the films 309a and 309b
The substrate 301 is displaced with respect to the substrate 301 in response to heat received through the substrate 4. The films 309a and 309b are also the films 307a and 307
As in the case of b, it may be made of any material having a different expansion coefficient,
The displacement direction of 09 is set to be the same as the displacement direction of the first displacement portion 307. That is, in this embodiment, the magnitude relationship of the expansion coefficient between the lower film 309a and the upper film 309b of the second displacement portion 309, the lower film 307a of the first displacement portion 307 and the upper film The material of each film is selected so that the magnitude relationship of the expansion coefficient with 307b is the same.

As shown in FIGS. 6C and 6D, when the reading light j ₀ enters the half mirror unit 308, a part of the reading light j ₀ is reflected by the half mirror unit 308 and the reflected light j ₁ is reflected. The rest of the readout light j ₀ incident on the half mirror unit 308 is transmitted through the half mirror unit 308 and reflected by the total reflection mirror 310, and is again reflected on the half mirror unit 3.
08 from the lower surface. Half mirror 30 from the bottom
Some of the re-incident read light 8 is transmitted light j ₂ transmitted through the half mirror 308. Between the transmitted light j ₂ and the reflected light j _1, there is an optical path length difference corresponding to twice the distance between the half mirror 308 and the total reflection mirror 310. Thus, interference in accordance with the optical path length difference between the reflected light j ₁ and transmitted light j ₂ occurs, the reflected light j ₁ and transmitted light j ₂ is corresponding to the optical path length difference (thus, the first displacement Interference light having an interference intensity (according to the relative displacement between the section 307 and the second displacement section 309) is emitted from the half mirror section 308. Since the interference intensity of the interference light and the intensity of the transmitted light j ₂ and the intensity of the reflected light j ₁ is strongest when equal, it is desirable that the reflectance of the half mirror 308 at about 38%.

As can be seen from the above description, in the present embodiment, the half mirror section 308 and the total reflection mirror 310
But it receives the reading light j _0, in place of the interference light which has a relative interference state according to the displacement between the reading light j ₀ that is received with the first displacement portion 307 and the second displacement portion 309 constitute an interference means to emit, in turn, receives the reading light j _0, the first displacement portion 3 to the reading light j ₀ that is received
A light action unit that gives a change according to the relative displacement between the second displacement unit 07 and the second displacement unit 309 and emits the read light that has changed is configured.

In this embodiment, as shown in FIG. 7, the first and second supported portions 303 and 305, the half mirror portion 308, the total reflection mirror 310, and the leg portions 302 and 304 are unit pixels (unit elements). ), The pixels are two-dimensionally arranged on the substrate 301.

The converter according to the present embodiment is similar to the converter shown in FIG.
(C) (d) and FIG. 7, a half mirror unit 3 of the light acting portion of the reading light j ₀ irradiated
8 for masking light other than the interference light emitted from 08
11 is provided. The mask 311 includes the half mirror unit 3
An opening 311a is provided in a region corresponding to 08. The mask 311 is, for example, the mask 21 shown in FIG.
1 can be formed. Although the interference light coming from the half mirror unit 308 of the reading light j ₀ to be irradiated is a signal light, the signal other than light of readout light (i.e., noise light) when the mix in the optical signal , So-called S / N is reduced. In this regard, according to the present embodiment, since the mask 311 is provided, the noise light does not mix with the signal light, and the S / N is improved. However, in the present invention, it is not always necessary to provide the mask 311.

The optical readout type radiation-to-displacement converter shown in FIGS. 6 and 7 can also be manufactured by using a semiconductor manufacturing process.

FIGS. 6 and 7 used in the present embodiment.
According to the optical readout type radiation-displacement converter shown in FIG. 6, infrared rays i are incident from below in FIGS. 6 (c) and 6 (d). The infrared light i is transmitted through the substrate 301, absorbed by the infrared absorbing film 306, and converted into heat. The heat generated in the infrared absorbing film 306 is transmitted to the displacement part 307, and the displacement part 307 curves upward or downward and inclines according to the heat. The second supported portion 305 has no infrared absorbing film, and the displacement portion 309 is not displaced by the infrared light i. On the other hand, the readout optical system described later uses a readout light j _{0 of} visible light.
Is incident from above in FIGS. 6C and 6D through the opening 311 a of the mask 311 and is irradiated on the half mirror unit 308. As a result, as described above, the readout light j ₀ incident on the half mirror 308 displaced portion 307,30
The light is changed to interference light having an interference state according to the relative displacement between the light beams 9 and the interference light is emitted from the half mirror unit 308 upward in FIGS. 6C and 6D. Accordingly, the infrared light i incident on the infrared absorbing film 306 is converted into an interference state of the read light, and the infrared light can be detected based on the interference light as described later.

Also in the present embodiment, since the technology for detecting a minute displacement called interference with high sensitivity is applied to infrared detection, detection with higher sensitivity than before can be performed, and furthermore, high sensitivity and infrared detection can be achieved. An image can be formed.

Further, in the present embodiment, instead of converting infrared rays into a resistance value (electric signal) through heat, the infrared rays are converted into heat and displacement in the same manner as in the first and second embodiments. Is converted into a change in readout light through the
There is no need to supply an electric current to the supported portion 303 supported by the above, and no self-heating occurs in the supported portion 303. Therefore, according to the present embodiment, since heat is detected only by the incident infrared light, the S / N is improved, the detection accuracy is improved, and an infrared image can be formed with high detection accuracy. . Needless to say, in the present embodiment, the cooler that was required in the quantum infrared detector is not required.

By the way, the first displacement portion 307 not only displaces due to the heat from the infrared absorbing film 306 due to the incident infrared light i, but also when the external temperature changes, the temperature of the substrate 301 changes due to the influence thereof. Although the thermal resistance is large, the first displacement portion 3 is formed via the leg portion 302.
Since it is transmitted to 07, it is also displaced by this.
However, in the present embodiment, the second displacement portion 309 is displaced in the same direction as the displacement portion 309 with respect to the substrate 301 in accordance with heat received from the substrate 301;
Relative displacement between the first and second displacement portions 309 (therefore, the relative displacement between the half mirror portion 308 and the total reflection mirror 310) is based on the incident infrared light, excluding the influence of external temperature. i approaches the displacement of the first displacement portion 307 caused only by the heat from the infrared absorbing film 306. Therefore, in the optical readout radiation-to-displacement converter itself, the change in the interference state of the interference light obtained from the half mirror unit 308 is less affected by the temperature change of the substrate 301 itself. Therefore, the temperature controller 1 in FIG.
In 09, it is not necessary to perform strict control, and cost can be reduced.

The first temperature with respect to the temperature of the substrate 301
When the displacement amounts of the second displacement portions 307 and 309 are made substantially equal, the influence of the external temperature can be almost completely canceled, which is preferable. In this case, specifically,
The first and second displacement parts 307, 309 may be made of the same material and the same dimensions.

Further, the first temperature with respect to the temperature of the
When the thermal change time constants of the second displacement portions 307 and 309 are made substantially equal, the influence of a transient temperature change due to the influence of an external temperature can be canceled, which is preferable. In this case, specifically, since the thermal resistance of the legs 302 and 304 is greater than the thermal resistance of the other members, the lengths and thicknesses of the legs 302 and 304 are adjusted, and the thermal resistance of both members is adjusted. Are kept equal. Further, the infrared absorbing layer 306, the first displacement part 307, and the half mirror part 308
And the heat capacity of the second supported portion 305 made up of the second displacement portion 309 and the total reflection mirror 310 is equalized. If the thermal resistance and the thermal capacity are made equal, the thermal time constant becomes equal.
Even if both the thermal resistance and the thermal capacity are not necessarily equal, the product of the thermal resistance and the thermal capacity may be made equal.

In this embodiment, as described above, the infrared absorbing film 306 is thermally connected to the first displacement portion 307, but does not move even if the first displacement portion 307 is displaced. It has a structure. Therefore, even if the absorption rate is increased by increasing the thickness of the infrared absorbing film 306, the displacement portion 30
7 does not hinder the ease of movement.

In this embodiment, the half mirror section 308 and the total reflection mirror 310 may be exchanged.
In that case, it may be irradiated with reading light j ₀ from below. In the present embodiment, the first supported portion 30
3 as the second floor portion and the second supported portion 305
Is the first floor portion, but conversely, the first supported portion 3
03 as the first floor portion and the second supported portion 30
5 may be a second floor portion. In this case, the read light j ₀
When irradiating from below, the structure may be as it is,
Half mirror 308 when irradiating the reading light j ₀ as with the present embodiment from above and the total reflection mirror 310
Can be replaced with

In addition to the above, according to the present embodiment,
The same advantages as in the second embodiment can be obtained.

(Fourth Embodiment) Next, a fourth embodiment of the present invention will be described.
8 and 9 with respect to the imaging device according to the embodiment of FIG.
This will be described with reference to FIG.

FIGS. 8 and 9 are views showing an optical readout type radiation-to-displacement converter used in an imaging apparatus according to a fourth embodiment of the present invention. FIG. 8B is a cross-sectional view taken along line HH ′ in FIG. 8A, and FIG. 8C is a cross-sectional view taken along line EE in FIG. 8A. Sectional view along line ', FIG. 9 (a)
FIG. 9 is a sectional view taken along the line FF ′ in FIG.
FIG. 9B is a sectional view taken along line GG ′ in FIG.

The imaging device according to the present embodiment differs from the imaging device according to the first embodiment only in the configuration of the converter 100 and the configuration of the readout optical system 101 in FIG. Duplicate description of other parts is omitted. Further, the readout optical system used in the present embodiment is the same as the readout optical system shown in FIG. 5 used in the second and third embodiments, and therefore, the duplicated description of the readout optical system is omitted. I do.

In the imaging apparatus according to the present embodiment, the converters shown in FIGS. 8 and 9 are used as converter 100 in FIG.

The converter shown in FIGS. 8 and 9 includes a substrate 351 as a base, a first supported portion 353 supported on the substrate 351 via legs 352, and a leg 3.
A second supported portion 355 supported on the substrate 351 in a state where the second supported portion 355 is suspended via the substrate 54. In the present embodiment, the first and second supported portions 353 and 355 are provided at substantially the same height.

In this embodiment, the supported portions 353 and 355 are provided on the substrate 351, and the infrared light i is incident from below the substrate 351 and the readout light j 0 _is incident from above the substrate 351. Therefore, the substrate 351 is made of a material that transmits infrared rays i. However, when the reading light j ₀ is incident from below the substrate 351 and the infrared light i is incident from above the substrate 351, the substrate 351 may be made of a material that transmits the reading light. In this case, for example,
The half mirror section 358 described later may be a total reflection mirror, and the total reflection mirror 361 described later may be a half mirror. However, if an opening is formed in a desired passage region of the infrared light or the readout light on the substrate 351, the substrate 3
The material of 51 is not limited at all.

In the present embodiment, the first supported portion 353
Has the same configuration as the supported portion 303 of the second floor portion in FIG. That is, the first supported portion 353 is
An infrared absorbing film 356 which is directly fixed to the center 52 and is arranged at the center and receives infrared rays and converts the infrared rays into heat;
6, one end portion is fixed to each of the infrared absorbing films 356
And the readout light j fixed to the free end side of each of the displacement portions 357 and arranged so as to surround the infrared absorbing film 356 together with the displacement portions 357 in a U-shape.
A half mirror unit 358 that reflects only a part of ₀ . The displacement section 357 forms a cantilever. Also in the present embodiment, the infrared absorbing film 356
Is thermally connected to the displacement section 357, but the displacement section 3
The structure does not move even if 57 is displaced. Substrate 35
In a region on the first surface facing the half mirror unit 358, a total reflection mirror 361 is formed as a reflection unit for reflecting the read light transmitted through the half mirror unit 358.

The displacement part 357 is, like the first displacement part 307 in FIG.
357b. Films 357a and 357b
Are made of different substances having different expansion coefficients, and constitute a so-called thermal bimorph structure.

The materials of the legs 352 and 354, the infrared absorbing film 356, and the films 357a and 357b are the same as those of the legs 302 and 304, the infrared absorbing film 306, and the films 307a and 307b in FIG. Materials can be used.

As shown in FIGS. 8 (c) and 9 (a),
When the read light j ₀ enters the half mirror unit 358,
The read light j ₀ part has been reflected light j ₁ becomes reflected by the half mirror 358 of the remaining reading light j ₀ incident on the half mirror 358 by the total reflection mirror 361 is transmitted through the half mirror 358 The light is reflected and enters the half mirror portion 358 again from the lower surface. Part of the read light again incident from the lower surface to the half mirror 358 is transmitted light j ₂ transmitted through the half mirror 358. Between the transmitted light j ₂ and the reflected light j _1, the half mirror 3
There is an optical path length difference corresponding to twice the spacing between 58 and total reflection mirror 361. Therefore, interference occurs in response to the optical path length difference between the reflected light j ₁ and transmitted light j _2, the reflected light j ₁ and transmitted light j ₂ is corresponding to the optical path length difference (and therefore, the displacement portion 357 Interference light having an interference intensity (corresponding to the displacement) is emitted from the half mirror unit 358. It is desirable that the reflectance of the half mirror section 358 be about 38%.

As can be understood from the above description, in the present embodiment, the half mirror section 358 and the total reflection mirror 361
But receives the reading light j _0, constitute an interference means to be emitted instead of the interference light which has an interference state corresponding to the reading light j ₀ which has received the displacement of the displacement portion 357, and thus,
Receiving the reading light j _0, constitute the optical action section for emitting a reading light the change giving change corresponding to the displacement of the displacement portion 357 to the read beam j ₀ that is received.

In the present embodiment, the second supported portion 355
Are arranged on both sides of the first supported portion 353, respectively. The second supported portion 355 has a displacement suppressing portion 359 whose one end portion is directly fixed to the leg portion 354, and the displacement suppressing portion 359 forms a cantilever. The displacement suppressing section 359, like the displacing section 357, is composed of two films 359a and 359b overlapping each other. The films 359a and 359b are made of different materials having different expansion coefficients, and form a so-called thermal bimorph structure. The films 359a and 359b are the films 3
Similarly to 57a and 357b, it may be made of any material having an expansion coefficient different from each other.
57 is set to be opposite to the displacement direction.
That is, in the present embodiment, the magnitude relationship of the expansion coefficient between the lower film 359a and the upper film 359b of the displacement suppression unit 359, the lower film 357a of the displacement unit 357 and the upper film 35
The material of each film is selected so that the magnitude relationship of the expansion coefficient with 7b is reversed. The free end side of the displacement suppressing section 359 is mechanically coupled to the half mirror section 358 via the coupling section 360 having a large thermal resistance, and is further mechanically coupled to the displacement section 357. Therefore, in the present embodiment, the displacement suppressing unit 359 is a displacement unit 35 for increasing or decreasing heat.
7 in the direction opposite to the displacement direction.
The displacement of the displacement portion 357 is suppressed by trying to displace with respect to the substrate 351 in accordance with the heat received via the first and second substrates.

Although not shown in the drawings, the first and second supported portions 353, 35
5, the half mirror unit 358, the total reflection mirror 361, and the legs 352, 354 are unit pixels (unit elements), and the pixels are two-dimensionally arranged on the substrate 351.

Also in this embodiment, as shown in FIGS. 8 and 9, a mask 362 similar to the mask 311 in FIGS. 6 and 7 is provided. The mask 362 is
An opening 362a is provided in a region corresponding to the half mirror portion 358.

The optical readout type radiation-to-displacement converter shown in FIGS. 8 and 9 can also be manufactured by using a semiconductor manufacturing process.

FIGS. 8 and 9 used in the present embodiment.
According to the optical readout type radiation-displacement converter shown in FIG. 8, the infrared ray i is incident from below in FIGS. 8 (b), (c) and FIG. The infrared rays i pass through the substrate 351 and are absorbed by the infrared absorbing film 356 to be converted into heat. The heat generated in the infrared absorbing film 356 is transmitted to the displacement portion 357, and the displacement portion 357 is curved upward or downward and tilts according to the heat. On the other hand, the reading optical system, the reading light j ₀ of the visible light is irradiated to FIG 8 (b) (c) and the half mirror 358 is incident through the opening 362a of the mask 362 from above in FIG. 9 . As a result, as described above, the read light j ₀ incident on the half mirror unit 358 is changed to an interference light having an interference state corresponding to the displacement of the displacement unit 357, and the interference light is transmitted from the half mirror unit 358 to the half mirror unit 358 in FIG. (B) It is emitted upward in (c) and FIG. Therefore, the infrared light i incident on the infrared absorbing film 356 is converted into the interference state of the read light, and the infrared light can be detected based on the interference light.

Also in the present embodiment, since the technique for detecting a minute displacement called interference with high sensitivity is applied to infrared detection, detection with higher sensitivity than before can be performed, and furthermore, high sensitivity and infrared detection can be achieved. An image can be formed.

In this embodiment, as in the first to third embodiments, the infrared rays are not converted into a resistance value (electric signal) via heat, but the infrared rays are converted into heat and displacement. Since the light is converted into a change in readout light through the
There is no need to supply current to the supported portion 353 supported by, and no self-heating occurs in the supported portion 353. Therefore, according to the present embodiment, since heat is detected only by the incident infrared light, the S / N is improved, the detection accuracy is improved, and an infrared image can be formed with high detection accuracy. . Needless to say, in the present embodiment, the cooler that was required in the quantum infrared detector is not required.

By the way, the displacement portion 357 not only displaces due to the heat from the infrared absorbing film 356 due to the incident infrared light i, but also when the external temperature changes, the temperature of the substrate 351 changes due to the influence. Even though the thermal resistance is large, the thermal resistance is transmitted to the displacement portion 357 via the leg 352, so that the displacement is attempted. However, in the present embodiment, the displacement suppressor 359 attempts to displace the substrate 351 in response to the heat received from the substrate 351 in a direction opposite to the direction of displacement of the displacement 357 with respect to the increase and decrease of the heat. Therefore, the displacement part 35 is eventually
The displacement of 7 comes close to the displacement caused only by the heat from the infrared absorbing film 356 due to the incident infrared light, excluding the influence of the external temperature. Therefore, similarly to the third embodiment described above, the half mirror unit 358
The influence of the temperature change of the substrate 351 itself on the change in the interference state of the interference light obtained from the above is reduced. For this reason, it is not necessary to perform strict control in the temperature controller 109 in FIG. 1, and cost can be reduced.

In the present embodiment, the amount of displacement of the displacement section 357 with respect to the temperature of the substrate 351 and the amount of displacement of the displacement suppression section 359 with respect to the temperature of the substrate 351 are made substantially equal. In this case, the influence of the external temperature change can be almost completely canceled, which is preferable. In this case, specifically, the displacement section 357 and the displacement suppression section 359 may be manufactured with the same material and the same dimensions.

Further, the displacement portion 3 with respect to the temperature of the base 351
It is preferable to make the thermal change time constants of the 57 and the displacement suppressing unit 359 substantially equal, because even a transient temperature change due to the influence of an external temperature can be canceled out. In this case, specifically, the leg 352 and the leg 354
Since the thermal resistance of is larger than the thermal resistance of other members,
The lengths and thicknesses of the legs 352 and 354 are adjusted to make the thermal resistances of the two equal. In addition, the heat capacity of the first supported portion 353 including the infrared absorbing layer 356, the displacement portion 357, and the half mirror portion 358 is equal to the heat capacity of the second supported portion 355 including the displacement suppressing portion 359. If the thermal resistance and the thermal capacity are made equal, the thermal time constant becomes equal. Even if both the thermal resistance and the thermal capacity are not necessarily equal, the product of the thermal resistance and the thermal capacity may be made equal.

In this embodiment, as described above, the infrared absorbing film 356 is thermally connected to the displacement portion 357, but has a structure that does not move even if the displacement portion 357 is displaced. Therefore, even if the thickness of the infrared absorbing film 356 is increased to increase the absorptance, the ease of movement of the displacement portion 357 is not hindered.

If the displacement range of the displacement portion 357 is not limited, the intensity of interference repeats the intensity every half of the wavelength of the read light because of the difference in optical path length. Conversely, an inversion phenomenon in which the interference intensity is inverted occurs. Therefore, it is preferable to limit the displacement range of the displacement unit 357 to １ ／ or less of the wavelength of the read light so that the change in the interference intensity due to the displacement of the displacement unit 357 becomes a monotonous change. For example, when the temperature of the displacement portion 357 rises, the displacement portion 357 is bent downward in FIGS. 8B and 8C so that the half mirror portion 358 and the total reflection mirror 36 are bent.
If the interval from 1 is set to 1/4 or less of the wavelength of the reading light,
Even if excessive infrared rays are incident, the movement of the displacement section 357 stops at the point where the half mirror section 358 and the total reflection mirror 361 are in contact with each other. At this time, since the interference intensity becomes maximum, the inversion phenomenon does not occur. The above is the case where monochromatic light is used as the readout light. However, also when white light is used as the readout light, similarly, the displacement of the interference color due to the displacement of the displacement portion 357 becomes a monotonous change. The range of the displacement of 357 may be limited. It is needless to say that a special restricting portion for restricting the range of displacement of the displacement portion 357 may be provided.

In addition to the above, according to the present embodiment,
The same advantages as in the second embodiment can be obtained.

Although the embodiments of the present invention have been described above, the present invention is not limited to these embodiments.

[0157]

As described above, according to the present invention,
A radiation image can be visualized with high detection accuracy and sensitivity without requiring a cooler, and a stable radiation image can be obtained regardless of changes in the environmental temperature.

[Brief description of the drawings]

FIG. 1 is a schematic configuration diagram showing an imaging device according to a first embodiment of the present invention.

FIG. 2 is a diagram showing an optical readout radiation-displacement conversion device used in the imaging device according to the first embodiment of the present invention, and FIG. 2 (a) shows a cross section of the unit pixel in a predetermined state. FIG. 2B is a diagram schematically showing a cross section of the unit pixel in another state, and FIG. 2C is a view taken along the line AA ′ in FIG. 2A. (D) is a plan view showing the arrangement state of the pixels.

FIG. 3 is a schematic configuration diagram showing an optical configuration of the imaging device according to the first embodiment of the present invention.

FIG. 4 is a diagram showing an optical readout type radiation-to-displacement converter used in an imaging device according to a second embodiment of the present invention, and FIG. 4 (a) is a part schematically showing the converter; FIG. 4B is a cutaway plan view, and FIG.
It is an arrow view.

FIG. 5 is a schematic configuration diagram showing an optical configuration of an imaging device according to a second embodiment of the present invention.

FIG. 6 is a diagram showing an optical readout radiation-to-displacement converter used in an imaging device according to a third embodiment of the present invention, and FIG.
FIG. 6 is a plan view schematically showing the second floor portion of the floor structure.
FIG. 6B is a plan view schematically showing the first floor portion, and FIG.
6C is a cross-sectional view taken along line CC ′ in FIGS. 6A and 6B, and FIG. 6D is a cross-sectional view taken along line DD ′ in FIGS. 6A and 6B. FIG.

FIG. 7 is a plan view showing an arrangement state of pixels of the optical readout radiation-displacement converter shown in FIG. 6;

FIG. 8 is a diagram showing an optical readout radiation-displacement converter used in an imaging device according to a fourth embodiment of the present invention. FIG. 8A schematically shows a unit pixel (unit element) thereof. 8B is a plan view of FIG. 8B, and FIG.
FIG. 8C is a sectional view taken along the line H ′, and FIG.
It is sectional drawing which followed the -E 'line.

FIG. 9 is a diagram showing an optical readout radiation-to-displacement converter used in an imaging device according to a fourth embodiment of the present invention, and FIG. 9 (a) is FF in FIG. 8 (a). 9B is a cross-sectional view taken along a line GG ′ in FIG. 8A.

[Explanation of symbols]

 REFERENCE SIGNS LIST 100 optical readout radiation-displacement converter 101 readout optical system 102 container 102 a, 102 b window 103 exhaust pipe 104 space 105 temperature stabilizer 106 heat transfer plate 107 temperature sensor 108 gas molecule adsorbent 109 temperature controller 110 heat shield

Claims (5)

[Claims] 1. A one-dimensional or two-dimensional element, wherein each element generates heat by receiving radiation, generates a displacement corresponding to the heat, and gives a readout light received with a change corresponding to the displacement to emit the readout light. An optical readout radiation-displacement converter having a plurality of elements arranged in a dimension, and irradiating each element with the readout light, and each element based on the changed readout light emitted from each element A readout optical system for forming an optical image corresponding to the displacement, and a sealed container containing the optical readout type radiation-displacement converter, wherein the window transmits the radiation and the window transmits the readout light. A temperature stabilizer for keeping a temperature of a predetermined portion of the optical readout radiation-displacement converter substantially constant; and a temperature stabilizer of the predetermined portion of the optical readout radiation-displacement converter. Direct or A temperature sensor for indirectly detecting, based on a detection signal from the temperature sensor, the temperature stabilization such that the temperature of the predetermined portion of the optical readout radiation-displacement converter is kept substantially constant. And a temperature controller for controlling the imager. 2. The imaging apparatus according to claim 1, wherein the space in the container is set to 1 atm or less or substantially evacuated. 3. The imaging device according to claim 2, wherein a gas molecule adsorbent is provided in the container. 4. The imaging device according to claim 1, wherein the temperature stabilizer is accommodated in the container. 5. A heat shield, thermally coupled to said temperature stabilizer, for reducing the transfer of unwanted thermal energy to said optical readout radiation-to-displacement converter, is provided within said container. The imaging device according to any one of claims 1 to 4, wherein: